Influencer marketing: explaining the effects of influencer self-presentation strategies on brand responses through source credibility

Abstract

Purpose

Self-presentation is an important aspect of influencer marketing. Drawing upon self-presentation theory and source credibility theory, this study aimed to unravel how the self-presentation strategies of a layperson, opinion leadership and micro-celebrity influence source credibility (i.e. trustworthiness, expertise, physical attractiveness and social attractiveness) and how source credibility, in turn, affects brand responses.

Design/methodology/approach

An online experiment among female participants (N = 229) was conducted. Participants were shown a sponsored blog in which the influencer presented herself as either a layperson, an opinion leader or a micro-celebrity.

Findings

The study demonstrated that the presentation strategy of a layperson was more persuasive than a micro-celebrity presentation because of higher levels of (1) trust and (2) social attractiveness. In addition, opinion leaders were perceived as having more expertise than laypeople and, therefore, positively enhanced brand responses.

Research limitations/implications

The current findings provide relevant insights into the theoretical mechanisms (i.e. expertise, trustworthiness and social attractiveness) that explain the effects of self-presentation strategies on brand responses.

Practical implications

Our findings imply that credibility perceptions determine the persuasiveness of the SMI. This study showed that layperson and opinion leadership self-presentation strategies are relatively more persuasive.

Originality/value

This study is the first to show that influencers’ self-presentation strategies determine how people respond to the brands that influencers promote. In addition, we show that these effects are explained by the influencers’ trust, social attractiveness and expertise.

Citation

van Reijmersdal, E.A., Walet, M. and Gudmundsdóttir, A. (2024), "Influencer marketing: explaining the effects of influencer self-presentation strategies on brand responses through source credibility", Marketing Intelligence & Planning, Vol. 42 No. 7, pp. 1214-1233. https://doi.org/10.1108/MIP-03-2023-0125

Recently, the popularity of influencer marketing – the establishment of partnerships between brands and social media influencers – has grown exponentially (Audrezet et al., 2020; Abhishek and Srivastava, 2021; Lee and Lee, 2022). Social media influencers (SMIs) are internet users who accumulate a significant following on social media through the textual and visual narration of their personal lives and lifestyles (Abidin, 2014; Vrontis et al., 2021). SMIs engage with their following and monetize their following by integrating paid persuasive messages into their blogs or other social media posts (Abidin, 2014; Kim and Read, 2022; Vrontis et al., 2021).

The online image or personality of SMIs is likely to determine how audiences respond to the promoted brands (Rifon et al., 2016). SMIs create strategic posts in which they carefully control how the audience views them. This process of crafting a virtual identity is called the presentation of oneself. Influencers are known to have mastered the strategic skill of self-presentation through careful curation as part of their self-branding (Duffy and Hund, 2015; Jin et al., 2019; Marwick, 2015).

Based on ethnographic fieldwork among influencers and content analyses of influencer posts (e.g. Abidin, 2014, 2016; Gudmundsdóttir and Chia, 2019; Marwick, 2015, 2016), three self-presentation strategies can be discerned: layperson, opinion leader and micro-celebrity. A few studies examined the effects of the presence of specific self-presentation elements (i.e. elements people use to present themselves online, such as character traits, values and beliefs or physical appearance) on consumers’ purchase intentions (e.g. Audrezet et al., 2020; Stallen et al., 2010). These studies show that self-presentation plays an important role in the persuasiveness of influencer and celebrity marketing. However, scientific knowledge on the effects of overarching self-presentation strategies on brand responses is limited. So far, there are no studies that show how the self-presentation of SMIs affects consumers’ responses to the brands that the SMI promotes. This study aims to provide a better understanding of the effects of self-presentation strategies on the audiences of influencers. The present study adds to the literature by experimentally examining how influencer self-representation strategies are related to specific brand responses (i.e. brand attitude, product attitude and purchase intention).

Source credibility theory may explain why some self-presentation strategies exert more influence on consumers’ brand responses than others (Hovland et al., 1953; Ohanian, 1990). Source credibility refers to characteristics that make one a believable source of information in the eyes of receivers, including trustworthiness, expertise and attractiveness (Cheung and Thadani, 2012). These three dimensions are all found to play key roles in influencing attitudes and behaviors (Chu and Kamal, 2008; Munukka et al., 2016). Given the importance of credibility for persuasion (Eisend, 2006; Pornpitakpan, 2004), it is plausible that SMIs try to influence credibility perceptions through self-presentation. Moreover, each unique self-presentation strategy might trigger different aspects of credibility among the audience (Jin et al., 2019). A recent bibliometric analysis called for more attention to authenticity and credibility when studying influencer marketing (Abhishek and Srivastava, 2021). In particular, in relation to self-presentation, credibility seems crucial. Previous studies on influencer self-presentation strategies and source credibility were either qualitative (Abidin, 2014, 2016; Duffy and Hund, 2015; Marwick, 2015, 2016; McQuarrie et al., 2013) or correlational (Gudmundsdóttir and Chia, 2019) in nature. The present study adds to the literature by examining the causal relationships between influencers’ self-presentation strategies and source credibility.

Although the effects of source credibility on brand responses have been investigated before (e.g. Eisend, 2006; Martensen et al., 2018; Munukka et al., 2016; Pornpitakpan, 2004), so far no study has empirically examined within one study whether source credibility explains the effectiveness of influencer self-presentation on brand responses. Drawing upon self-presentation and source credibility theory (Abidin, 2014, 2016; Gudmundsdóttir and Chia, 2019; Hovland et al., 1953; Marwick, 2015, 2016; Ohanian, 1990), the present study adds to the literature by investigating the relations between influencer self-presentation strategies, source credibility dimensions and brand responses in one mediation model. As such, we provide theoretical insights into the mechanisms that underlie self-presentation effects on persuasion.

This study will provide more insights into which kind of influencer is most persuasive for influencer marketing. This knowledge can guide marketers and advertisers in the process of selecting specific types of influencers for their campaigns.

Theoretical background

Self-presentation theory

Self-presentation refers to attempts to control or shape how the audience views the self, intending to create a desired impression (Goffman, 1978). As such, self-presentation is part of a broader set of behaviors called “impression management” (Krämer and Winter, 2008). This entails making conscious decisions to reveal certain aspects of oneself and to conceal others. Impression management is specifically relevant in the context of SMIs, as affordances of the Internet (e.g. asynchronous communication) give SMIs control to selectively disclose personal information and hence more carefully craft impressions than face-to-face interactions (Krämer and Winter, 2008).

It is argued that influencers can create overarching personas with their self-presentation strategies (Leban et al., 2020). Influencers have a dominant self-presentation strategy but sometimes use other strategies to connect with their audience in different ways (Duffy and Hund, 2015; Carr and Hayes, 2014). The next section elaborates on three main self-presentation strategies: layperson, opinion leader and micro-celebrity (Abidin, 2014, 2016; Gudmundsdóttir and Chia, 2019; Marwick, 2015, 2016).

Self-presentation strategies

When using the layperson strategy, SMIs highlight the “normal” side of life rather than only showing the positives. Marwick (2016) refers to this as livestreaming. This requires authenticity and realness, arguably the most valued qualities of SMIs (Duffy and Hund, 2015; Marwick, 2015; McQuarrie et al., 2013). Laypeople, for example, can be described as normal people who may also show the imperfect aspects of their lives by sharing everyday struggles or the mistakes they make (Lehto, 2022). Furthermore, laypeople typically reveal intimate, personal information to others, such as personal thoughts, intimate feelings, values and beliefs (Bazarova et al., 2013). These aspects make these kinds of influencers more relatable and enhance the feeling of them being more close (Munaro et al., 2021). Compared to influencers who use other strategies, influencers that use the layperson self-presentation strategy do not necessarily struggle more in their lives, but it is what they choose to show of it. They deliberately present themselves as people like you and me and show their weaknesses (Leite and Baptista, 2022).

In the opinion leader strategy, SMIs want to present themselves as experts on a certain topic and as having opinions valued by others. Opinion leaders are generally defined as people who are more experienced and who are aware of the latest trends (Shoham and Ruvio, 2008). SMIs, for example, highlight their opinion leadership by mentioning that they are being recognized by third parties (e.g. other influencers or traditional media) as a legitimization of their influence. They also show who they know to emphasize their leading position (Farivar et al., 2021; Marwick, 2016). This so-called third-party recognition can persuade prospective followers based on the heuristic of social proof (Cialdini, 2006). That is, if others think this is good, it must be good.

When using the micro-celebrity strategy, SMIs incorporate celebrity elements (i.e. aspects normally confined to celebrities) in their posts, such as a status of wealth and fame (Marwick, 2016). Duffy and Hund (2015) refer to this strategy as “staging the glam life,” for example by portraying an extravagant lifestyle similar to traditional celebrities, including luxury and glamor (Gudmundsdóttir and Chia, 2019; Marwick, 2016) and by showcasing social connections to well-known people (Abidin, 2014). These SMIs usually attempt to maximize the aesthetics of their photos to resemble professional photography found in advertisements and (fashion) magazines (Colucci and Cho, 2014).

Source credibility theory

Source credibility theory proposes that more credible sources will also be more persuasive, even when the content of the message is objectively the same (Hovland et al., 1953; Ohanian, 1990). Source credibility comprises trustworthiness, expertise and attractiveness (Ohanian, 1990), and the latter can be divided into physical attractiveness (Patzer, 1983) and social attractiveness (Hong et al., 2012). For influencers, in particular, this distinction between physical and social attractiveness seems relevant because some of them use their physical attractiveness, whereas others try to leverage their social attractiveness as a means to gain an audience (Duffy and Hund, 2015; Leite and Baptista, 2022; Marwick, 2016).

Trustworthiness

Trustworthiness is the degree of confidence in and reliability of the endorser (Ohanian, 1990). In particular, layperson and opinion leadership self-presentations focus on enhancing perceived trust. Influencers using the laypeople strategy try to increase perceived trust by showing personal and imperfect aspects of their lives. By doing so, these SMIs show they dare to be transparent, which is a useful truth-telling technique and crucial to gaining consumers’ trust (Leite and Baptista, 2022; Martensen et al., 2018). This can be considered a form of intimate self-disclosure (Leite and Baptista, 2022), which has been found to positively affect source credibility, trust and purchase intentions (Leite and Baptista, 2022).

Opinion leaders try to increase perceived trust by emphasizing their knowledge and experience. The literature posits that opinion leaders are valued because of who they are, what they know (their expertise) and also who they know (Farivar et al., 2021). By showing that they are asked for advice by others, including by followers and in the media, they emphasize their opinion leader role (Winter and Neubaum, 2016). As such, they become trusted sources of information within their field of expertise (Farivar et al., 2021).

Both the opinion leadership and layperson strategies stand in contrast with the micro-celebrity strategy. Micro-celebrities incorporate celebrity elements, such as luxury and fame, thereby highlighting their social status (Marwick, 2016). Subsequently, SMIs mostly highlight positive aspects of their lives when using a micro-celebrity strategy, making them less open and transparent. Therefore, the audience might question whether micro-celebrities make valid assertions. Schouten et al. (2020) showed that in general, SMIs (i.e. influencers who present themselves as “ordinary,” approachable and authentic personalities) are more trustworthy than more traditional celebrities. Similarly, Gudmundsdóttir and Chia (2019) demonstrated that the micro-celebrity strategy correlated negatively with perceived trust. This study, therefore, assumes that the messages of laypeople and opinion leaders will result in higher levels of perceived trust than those of micro-celebrities.

In turn, the source credibility theory states that higher levels of perceived trust increase message persuasiveness (Hovland and Weiss, 1951; Hsu, 2023; Ohanian, 1990). In line with this assumption, prior research shows that trust positively impacts information credibility and could lead to positive brand attitudes (Munukka et al., 2016; Xiao et al., 2018), product attitudes (Huang, 2015) and purchase intentions (Herrando and Martin-De Hoyos, 2022). It is argued that in influencer marketing, consumers rely on subjective evaluations of influencers (Park and Kim, 2018). Therefore, the perceived trustworthiness of the influencer is important to enhance the perceived credibility of the endorsed brand. Research also showed that a trustworthy SMI could be a risk-reducing factor in the context of online marketing (Hong and Cho, 2011; Li et al., 2014). In an online setting, consumers cannot physically examine the endorsed product and therefore perceive more risk in purchasing the product (Li et al., 2014). However, if consumers trust the SMI, they feel less need to search for additional product information and are more likely to be persuaded (Hong and Cho, 2011; Li et al., 2014). Studies indeed showed that influencers who are perceived as opinion leaders generate more engagement (Casalo et al., 2020) and elicit higher intentions to purchase the product (Farivar et al., 2021). Also, sharing personal information, which characterizes the layperson strategy, has been found to enhance purchase intentions (Leite and Baptista, 2022). To test whether layperson strategies and opinion leader strategies indeed enhance persuasion through enhanced trust, we propose the following mediation hypothesis:

H1.

SMIs using (i) a layperson or (ii) an opinion leader self-presentation strategy score higher on perceived trustworthiness than SMIs using a micro-celebrity self-presentation strategy, which subsequently results in more positive (a) brand attitudes, (b) product attitudes and (c) higher purchase intentions.

Expertise

Expertise is the extent to which a source is qualified to provide valid and accurate information or discuss a particular subject (Hovland et al., 1953). The opinion leadership strategy most strongly focuses on highlighting expertise (Casalo et al., 2020). In general, opinion leaders’ beliefs are considered to be valuable (Farivar et al., 2021). Opinion leaders, for example, use third-party recognition to show that their opinions are valued by others and put emphasis on who they know (Farivar et al., 2021). Additionally, by emphasizing their expertise and qualifications in a certain field, opinion leaders try to create the impression that they are providing valuable information that non-experts would not be able to provide (Li and Du, 2011). Additionally, if influencers are perceived as opinion leaders, they are perceived to be more skilled and knowledgeable (Farivar et al., 2021; Lyons and Henderson, 2005). Subsequently, SMIs might be more likely to be perceived as experts when presenting themselves as opinion leaders than laypeople or micro-celebrities.

According to the source credibility theory, higher levels of perceived expertise increase message persuasiveness (Hovland et al., 1953; Ohanian, 1990). Several studies showed source expertise is positively related to attitudes toward the advertisement (e.g. Ohanian, 1990; Xiao et al., 2018) and increased purchase intentions (Pornpitakpan, 2004). According to the attribution theory (Kelley, 1967), expert sources are persuasive because people attribute a particular power and knowledge to them. People believe that expert sources provide more accurate and valid information than non-expert sources (e.g. Clark et al., 2012). A study on Instagram indeed showed that the advice of opinion leaders is more likely to be followed than advice from people who score lower on opinion leadership (Casalo et al., 2020). Subsequently, people are more likely to be persuaded by a SMI whom they perceive as an “expert.” Therefore, the following hypothesis is formulated:

H2.

SMIs using an opinion leader self-presentation strategy score higher on perceived expertise than SMIs using (i) a layperson or (ii) a micro-celebrity self-presentation strategy, which subsequently results in more positive (a) brand attitudes, (b) product attitudes and (c) higher purchase intentions.

Physical attractiveness

Physical attractiveness reflects receivers’ affection for the source related to physical cues, such as beauty, sexiness and elegance (Antil et al., 2012). The micro-celebrity strategy mainly focuses on enhancing perceived physical attractiveness. To do so, SMIs, for instance, maximize the aesthetics of their photos (Colucci and Cho, 2014) and mainly showcase a luxurious lifestyle (Duffy and Hund, 2015; Marwick, 2015). Gudmundsdóttir and Chia (2019) indeed showed that the micro-celebrity strategy could be linked to perceptions of physical attractiveness.

Contrary to micro-celebrities, laypeople and opinion leadership strategies do not specifically focus on enhancing perceptions of physical attractiveness. Laypeople predominantly portray the mundane aspects of life and are therefore less likely to focus on sharing a glamorous life. The main goal of the opinion leadership strategy is to be perceived as competent, which does not necessarily mean maximizing the aesthetics of photos or focusing on appearance. Therefore, it is assumed that, in particular, the micro-celebrity strategy reinforces perceptions of physical attractiveness.

According to Ohanian (1990) and Joseph (1982), physically attractive sources trigger more positive product responses because the perceived physical attractiveness of the source can spill over upon evaluations of the endorsed product (Trampe et al., 2010). It should be noted that this is only the case for product categories meant to enhance attractiveness (e.g. cosmetics, fashion and interior [1]), which could be explained by the meaning transfer model of McCracken (1989). This model (McCracken, 1989) argues that when an entity (i.e. the influencer) is paired with a brand – for example, when a celebrity endorses a brand in an advertisement – consumers infer that the meaning associated with the influencer applies to the brand or product as well. Drawing on this, the following hypothesis is formulated:

H3.

SMIs using a micro-celebrity self-presentation strategy score higher on physical attractiveness than SMIs using (i) a layperson or (ii) an opinion leader strategy, which subsequently results in more positive (a) brand attitudes, (b) product attitudes and (c) higher purchase intentions.

Social attractiveness

Social attractiveness refers to the attractiveness of the SMI as a friend or a person similar to oneself. To enhance social attractiveness, SMIs mostly use the layperson strategy. Laypeople try to increase the perceived similarity between their followers and themselves by disclosing intimate and personal information, such as deep personal feelings or daily problems (Bazarova et al., 2013; Gudmundsdóttir and Chia, 2019). It is theorized that disclosing such information gives the receiver a feeling of being appreciated and worth confiding in. This leads to higher likeability and appreciation of the influencer (Leite and Baptista, 2022). When the audience can easily relate to the mundane aspects of life that are shown by the layperson influencer, the affective ties with the SMI and the SMIs’ social attractiveness are expected to be enhanced (Gudmundsdóttir and Chia, 2019; Leite and Baptista, 2022; Marwick, 2015).

In contrast to laypeople, micro-celebrities and opinion leaders generally distance themselves from their followers. Micro-celebrities create social distance by portraying a luxurious and extravagant lifestyle that is only available for the “happy few” (Abidin, 2016). Opinion leaders try to distinguish themselves from their followers by enhancing their professional status and expertise (Casalo et al., 2020). As followers are less likely to relate to the extravagant lifestyles of micro-celebrities or the professional status of opinion leaders, they might lose interconnectedness with the SMI (Marwick, 2016). Therefore, it is assumed that the layperson strategy enhances perceptions of social attractiveness more than micro-celebrity and opinion leadership strategies.

Several studies showed that perceived (social) attractiveness positively affects attitudes and purchase intentions (e.g. Lou and Yuan, 2019; Schouten et al., 2020). This is because followers develop a sense of oneness between their own self-image and the image of the SMIs (Martensen et al., 2018). Generally, people think that others with similar characteristics also possess similar opinions (Kelley, 2013). Therefore, these opinions are perceived as more meaningful. Subsequently, messages from socially attractive SMIs are likely to positively affect brand and product attitudes and purchase intentions (Park et al., 2010). This results in the following hypothesis:

H4.

SMIs using a layperson self-presentation strategy score higher on social attractiveness than SMIs using (i) a micro-celebrity or (ii) an opinion leader self-presentation, which subsequently results in more positive (a) brand attitudes, (b) product attitudes and (c) higher purchase intentions.

Method

Design

This study employed a single-factor (self-presentation strategy: layperson vs opinion leader vs micro-celebrity) between-subjects design. Participants were exposed to a blog in which a female SMI presented herself using a specific self-presentation strategy. For this study, we selected a female blogger. This aligns with the fact that most influencers who create sponsored posts are women (Guttmann, 2020). The blogger is a sports influencer and an athlete from Belgium called Hanne. We chose this kind of influencer because of the popularity of sports influencers both among the audience and among advertisers (Lalli, 2018). To avoid any confounds related to gender identification, this study focuses on a female audience. Ethical approval was obtained for the pretest and the experiment from the institutional review board of the university.

Pretest

A pretest was conducted to examine whether the manipulated self-presentation strategies were perceived as intended. As this study was conducted during the COVID-19 outbreak, the blog topics (i.e. “How to stay fit?” and “How to keep your daily routine?”) were adjusted to the home quarantine situation to increase perceived relevance. We selected an influencer who was unknown in the country where the study was conducted, so we could manipulate her self-presentation style and participants would not have pre-existing perceptions of the influencer.

A total of 31 female participants (aged 19–30, 56.3% students) who did not participate in the main study were asked to answer questions related to each blog post. Participants scored the presence of layperson elements (e.g. “[Influencer] struggles with her life;” α = 0.79, M = 3.70, SD = 1.22); opinion leadership elements (e.g. “[Influencer] often receives questions/messages;” α = 0.66, M = 4.30, SD = 1.51) and celebrity elements (e.g. “[Influencer] lives a luxurious live;” α = 0.87, M = 4.35, SD = 1.78) on a scale ranging from 1 (strongly disagree) to 7 (strongly agree; Gudmundsdóttir and Chia, 2019). Additionally, participants were asked to rate six pictures on seven-point Likert scales ranging from 1 (strongly disagree) to 7 (strongly agree). For instance, participants were asked to what extent they thought the picture was professional, that it was edited and that it was showcasing Hanne’s expertise in sports.

Repeated measures ANOVAs showed that layperson blogs scored highest on layperson elements, opinion leader blogs scored highest on opinion leader elements and micro-celebrity blogs scored highest on micro-celebrity elements. Second, repeated measures ANOVAs showed that there were differences between the pictures in perceptions; therefore, the pictures that best represented the self-presentation strategies they were supposed to communicate were selected as visual stimulus material.

Stimulus material

Based on the pretest, three different blogs about sports motivation were created as stimulus materials for the main study; see Appendix. All fictitious blogs were presented as if they were from the same influencer. Each blog contained three parts. In the first part, the influencer was briefly introduced. The second part contained a story about the influencer’s life during home quarantine. In the layperson blog, the influencer wrote about her difficulties in life, such as her struggles to stay motivated to work out frequently. Also, she encouraged readers to provide feedback. In the opinion leader blog, the influencer emphasized her expertise in the sports branch and mentioned she often received questions from followers. In the micro-celebrity blog, the influencer presented her luxurious life (e.g. having a home gym) and connections to well-known people. Additionally, each blog included a different picture of the influencer related to her self-presentation strategy. For instance, the micro-celebrity picture looked like a professional photograph made in a studio, while the layperson picture was amateurish, having pixels and no professional light. The opinion leader picture showed the influencer being interviewed as an expert. The third part of the blog included a recommendation to wear sportswear from the brand 42|54. This brand was chosen as it creates high-fashion sportswear for women and is considered a relevant brand for the female target group. Thus, the blogs were identical, except for the second part and the pictures.

Sample and procedure

Participants were recruited through the university student pool. Beforehand, it was made clear that only females could participate. The students participated in the online experiment in exchange for research credits. They were provided with a link that led them to the questionnaire on the Qualtrics platform. We aimed for 225 students, and in total, 229 female students between 18 and 30 years old (M = 21.67, SD = 2.31) participated. Their average interest in sports wear was rather high (M = 5.62, SD = 0.96 on a seven-point scale), and they engaged in sports activities for 3–4 h a week indicating that the topic was relevant for the sample.

Participants were first asked to give informed consent and answer questions about demographics, after which they were randomly assigned to one of the three experimental conditions (layperson condition n = 79, micro-celebrity condition n = 76, opinion leader condition n = 74). After exposure to the blog, participants answered questions about the influencer’s credibility, followed by questions about attitudes toward the brand, product and purchase intentions. Then, questions related to the control variables were posed, after which participants were debriefed and thanked for their participation.

Measures

Trustworthiness, expertise and physical attractiveness were measured using seven-point semantic differential scales (Ohanian, 1990). Trustworthiness of the SMI was measured with “I think [Influencer] is: (1) unreliable/reliable; (2) undependable/dependable; (3) dishonest/honest; (4) insincere/sincere; (5) untrustworthy/trustworthy” (EV = 3.14, R² = 62.73%, Cronbach’s alpha = 0.84, M = 4.38, SD = 1.00). Expertise of the SMI was measured with “I think the [Influencer] is: (1) not an expert/expert; (2) inexperienced/experienced; (3) unknowledgeable/knowledgeable; (4) unqualified/qualified; and (5) unskilled/skilled” (EV = 3.66, R² = 73.28%, Cronbach’s alpha = 0.91, M = 4.78, SD = 1.06). Physical attractiveness of the SMI was measured with “I think [Influencer] is: (1) unattractive/attractive; (2) not classy/classy; (3) ugly/beautiful; (4) plain/elegant; (5) not sexy/sexy” (EV = 2.68, R² = 53.64%, Cronbach’s alpha = 0.78, M = 4.83, SD = 0.80). Finally, social attractiveness of the SMI was measured with five items on a scale ranging from 1 (strongly disagree) to 7 (strongly agree): “I feel like I know [Influencer],” “I think [Influencer] has a lot of things in common with me,” “[Influencer] feels familiar to me,” “[Influencer] feels close to me” and “I feel emotionally attached to [Influencer]” (Gudmundsdóttir and Chia, 2019; EV = 3.22, R² = 64.38%, Cronbach’s alpha = 0.86, M = 3.13, SD = 1.07). Factor analysis with varimax rotation showed that the items for the four mediators load on four different components. Accordingly, mean scores were calculated to create single measures of trustworthiness, expertise, physical attractiveness and social attractiveness.

Brand attitude was measured with a four-item, seven-point semantic differential scale (c.f. Van Noort and Van Reijmersdal, 2019). Participants indicated to what extent they considered the brand that was mentioned by the influencer as being “not very likable/very likable,” “not interesting/interesting,” “bad/good” and “not appealing/appealing” (Cronbach’s alpha = 0.88, M = 4.25, SD = 1.03).

Product attitude was measured with the same four-item seven-point semantic differential scale as brand attitude (Cronbach’s alpha = 0.90, M = 4.37, SD = 1.07). Purchase intention was assessed with three items on a seven-point semantic differential scale (Smink et al., 2019). These items asked participants to indicate the chance that they would buy sportswear from the brand as “improbable/probable,” “unlikely/likely” and “small/big” (Cronbach’s alpha = 0.97, M = 2.67, SD = 1.48).

Control variables were age, country of origin, weekly hours of sports activities (M = 3.72, SD = 2.17), experience with reading blogs about sports, product category involvement and recognition of the blog as being an advertisement. Product category involvement was measured using a five-item, seven-point semantic differential scale (Zaichkowsky, 1994): to what extent they found the product category of sportswear “unimportant/important,” “irrelevant/relevant,” “not beneficial/beneficial,” “non-essential/essential” and “worthless/valuable” (Cronbach’s alpha = 0.89, M = 5.62, SD = 0.96). Additionally, participants were asked whether they knew the influencer (0% yes) and the brand that was included in the blog (1% yes). If participants knew the brand, they were asked whether they owned products from the brand (0% yes). Further, they were asked whether they thought the blog was sponsored (96% yes).

A manipulation check was conducted to test whether the self-presentation strategy in the blogs was perceived as intended. The blogs were rated on nine items on a scale ranging from 1 (strongly disagree) to 7 (strongly agree). The first three items measured the presence of layperson elements: “[Influencer] struggles with her life”, “[Influencer] encourages feedback” and “[Influencer] shows imperfectness” (Cronbach’s alpha = 0.69, M = 3.70, SD = 1.22). The next three items measured the presence of opinion leader elements: “[Influencer] is known in traditional media,” “[Influencer] often receives questions/messages” and “[Influencer] has expertise in the sports branch” (α = 0.56, M = 4.37, SD = 0.97). The final three items measured the presence of micro-celebrity elements: “[Influencer] lives a luxurious life,” “[Influencer] has social connections to well-known people” and “[Influencer] uses filters in her picture” (Gudmundsdóttir and Chia, 2019; Cronbach’s alpha = 0.62, M = 4.44, SD = 1.13).

Results

Manipulation checks

A MANOVA was conducted with the self-presentation conditions as the independent variable and the measures for the presence of (1) layperson elements, (2) micro-celebrity elements and (3) opinion leader elements as the dependent variables. Results showed that the layperson blog scored significantly higher on layperson elements (M = 4.73; SD = 0.98) than the opinion leader (M = 3.39; SD = 0.92) and micro-celebrity blog (M = 2.93; SD = 0.96; F(2, 226) = 75.84, p < 0.001).

Additionally, the micro-celebrity blog scored significantly higher on micro-celebrity elements (M = 5.13; SD = 0.96) than the layperson (M = 4.04; SD = 0.96) and opinion leader blogs (M = 4.16; SD = 1.14), F(2, 226) = 26.13, p < 0.001. However, the opinion leadership blog did not score significantly higher on opinion leadership elements (M = 4.58; SD = 0.99) than the layperson (M = 4.29; SD = 0.99) and micro-celebrity blogs (M = 4.27; SD = 0.93; F(2, 226) = 2.39, p = 0.094). Thus, the manipulation was only partially successful.

Confound check

Further, correlational analyses were conducted to test whether the control variables were related to the mediators or dependent variables. These analyses only showed significant correlations between product involvement, participants’ experience reading blogs and the mediators and dependent variables. As these variables could affect the mediation path, product involvement and experience reading blogs were included as covariates in the analyses.

Hypotheses testing

Bootstrapping procedures (Hayes, 2017; Model 4; 5,000 bootstrap samples) were used to test the mediation hypotheses (H1–H4). For each dependent variable (i.e. brand attitude, product attitude and purchase intention), a separate analysis was conducted with the three self-presentation strategies as the independent multicategorical predictor variables and trustworthiness, expertise, physical attractiveness or social attractiveness as the mediating variables, depending on the hypothesis. Means and standard deviations for the mediating variables are presented in Table 1.

With respect to H1, the analyses showed a significant indirect effect of a layperson self-presentation (vs micro-celebrity) strategy on brand responses through perceived trust (Table 2). As predicted, participants who saw the blog with the layperson strategy thought the influencer was more trustworthy than those who saw the micro-celebrity strategy blog (b = 0.33, SE = 0.16, t = 2.12, p = 0.036), which in turn resulted in more positive brand attitudes (b = 0.47, SE = 0.06, t = 7.77, p < 0.001), product attitudes (b = 0.49 SE = 0.06, t = 8.00, p < 0.001) and higher purchase intentions (b = 0.52, SE = 0.09, t = 5.58, p < 0.001). However, results showed no significant indirect effect of an opinion leadership self-presentation strategy (vs micro-celebrity) on brand responses through perceived trust. Against expectation, the opinion leadership strategy did not result in significantly higher levels of perceived trust than the micro-celebrity strategy (b = 0.06, SE = 0.16, t = 0.39, p = 0.697). Therefore, H1 was partially accepted, that is, for the predicted effects of the layperson strategy versus the micro-celebrities, but not for the effects of the opinion leadership as compared to the micro-celebrities.

The results for H2 showed a significant indirect effect of an opinion leadership strategy when compared to layperson self-presentation on brand responses through perceived expertise (Table 2). As predicted, when participants saw the post with the opinion leadership strategy, they thought the influencer had more expertise than when they saw the layperson strategy post (b = 0.63, SE = 0.17, t = 3.79, p < 0.001), which in turn resulted in more positive brand attitudes (b = 0.42, SE = 0.06, t = 7.17, p < 0.001), product attitudes (b = 0.41, SE = 0.06, t = 6.64, p < 0.001) and higher purchase intentions (b = 0.43, SE = 0.09, t = 4.75, p < 0.001). However, the results showed no significant indirect effect of an opinion leader vs a micro-celebrity strategy on brand responses through perceived expertise. The opinion leadership strategy did not result in significantly higher levels of perceived expertise than the micro-celebrity strategy (b = 0.29, SE = 0.17, t = 1.73, p = 0.086). Thus, H2 was supported for the comparison between the opinion leader strategy and the layperson strategy but not for the comparison between the opinion leader and the micro-celebrity strategies, as there were no significant differences there.

The results for H3 showed no significant indirect effect of a micro-celebrity self-presentation (vs layperson and opinion leadership) on brand responses through perceived physical attractiveness (Table 2). Participants who saw the micro-celebrity strategy post did think the influencer was more physically attractive than the layperson (b = 0.04, SE = 0.13, t = 0.35, p = 0.730) or the opinion leader (b = −0.15, SE = 0.13, t = −1.17, p = 0.245). Thus, H3 was rejected.

With respect to H4, a significant indirect effect of layperson self-presentation (vs micro-celebrity) on brand responses through social attractiveness was found (Table 2). As predicted, participants who saw the layperson strategy post thought the influencer was more socially attractive than the micro-celebrity (b = 0.33, SE = 0.16, t = 2.04, p = 0.043), which in turn resulted in more positive brand attitudes (b = 0.45, SE = 0.06, t = 7.80, p < 0.001), product attitudes (b = 0.48, SE = 0.06, t = 7.93, p < 0.001) and higher purchase intentions (b = 0.70, SE = 0.08, t = 8.44, p < 0.001). However, results showed no significant indirect effect of layperson self-presentation (vs opinion leadership) on brand responses through social attractiveness. Participants who saw the layperson post did not think the influencer was more socially attractive than the opinion leadership post (b = 0.26, SE = 0.16, t = 1.59, p = 0.113). Therefore, H4 was accepted for the comparison between the layperson and the micro-celebrity but not for the comparison between the layperson and the opinion leader.

Conclusion and discussion

The current study contributes to existing research on self-presentation in the context of influencer marketing by unraveling the processes through which a layperson, opinion leadership and micro-celebrity self-presentation strategies affect brand responses. This study was the first to test how influencer self-presentation strategies cause source credibility perceptions and how the strategies are indirectly related to brand responses in an experimental design. Based on our findings, four main conclusions can be drawn.

First, laypeople are more persuasive than micro-celebrities because of (1) higher levels of perceived trust and (2) higher levels of perceived social attractiveness. Laypeople are perceived as more trustworthy and more socially attractive than micro-celebrities, leading to more positive attitudes toward the endorsed brand and product and higher purchase intentions. These findings add to the study of Gudmundsdóttir and Chia (2019), which showed that a layperson presentation style correlated significantly and positively with trustworthiness and social attractiveness, showing how this indirectly also affects persuasion. These findings corroborate earlier findings that show that the trustworthiness of endorsers is important for their persuasiveness (e.g. Munukka et al., 2016).

Second, opinion leaders are perceived as more experienced than laypeople and, therefore, they are more persuasive. When a blogger presents herself as an opinion leader instead of a layperson, she scores higher on perceived expertise, enhancing attitudes toward the endorsed brand and product and increasing purchase intentions. The current findings are in line with the conclusions of Lyons and Henderson (2005): the audience perceives opinion leaders as more knowledgeable and experienced, which consequently enhances persuasion (Hovland et al., 1953; Ohanian, 1990). However, the opinion leader was not perceived as more trustworthy than the micro celebrity. This may be explained by our manipulations: the manipulation check showed that the opinion leader was not perceived to be more of an opinion leader than the micro-celebrities. Thus, this may explain why they were equally trusted.

Third, the layperson strategy did not result in higher levels of social attractiveness than the opinion leadership strategy. This expectation was based on the findings of Casalo et al. (2020), who argued that opinion leaders try to create a distance between themselves and their followers by enhancing their professional status and expertise. However, while the blogger did showcase her professional status and expertise, this might not necessarily increase the perceived distance from the audience. Arguably, followers only lose interest in detached, inaccessible and commercialized micro-celebrities that erode the initial appeal of relatability and authenticity (Marwick, 2016).

Fourth, there is no difference in brand responses between the self-presentation strategies through physical attractiveness. Contrary to what was expected, the micro-celebrity strategy did not result in higher levels of physical attractiveness than the other two strategies. It could be the case that the aspect of physical attractiveness in the context of influencer marketing is normalized in the minds of the audience. Ohanian (1990) already argued that there is a widespread use of attractive endorsers in advertisements, such as athletes and fashionistas. Respondents might start to perceive physical attractiveness as a “common characteristic” among SMIs (Pornpitakpan, 2004).

Theoretical and practical implications

The objective of this study was to unravel the theoretical mechanisms that underlie the effects of SMI self-presentation strategies on brand responses. Several studies have demonstrated that the presence of specific presentation elements alters message persuasiveness (e.g. Stallen et al., 2010). However, this study was the first to focus on the effects of three overarching self-presentation strategies on message persuasiveness and the mediating role of source credibility. This study showed that the way in which influencers present themselves is important for the persuasiveness of their message. By adding this nuance to the literature, this study contributes to our theoretical understanding of how influencers affect the attitudes and behaviors of their followers.

The current findings also provide relevant insights into the theoretical mechanisms (i.e. expertise, trustworthiness and social attractiveness) that explain the effects of self-presentation strategies on brand responses. This study implies that a layperson’s self-presentation strategy results in more positive brand responses through (1) perceived trust and (2) social attractiveness than a micro-celebrity strategy. Additionally, this study shows that an opinion leadership self-presentation results in more positive brand responses through expertise than a layperson strategy. Some of the relations between the self-presentation strategies and these theoretical mechanisms were found in previous studies (e.g. layperson influencers were perceived as more trustworthy and more socially attractive by Gudmundsdóttir and Chia (2019) and opinion leaders were found to have more expertise by Lyons and Henderson (2005)), but we now experimentally show that these are underlying mechanisms that explain why self-presentation strategies have differential effects on persuasion. As such, this study enhances our understanding of the theoretical processes that underlie the persuasiveness of SMI self-presentation strategies.

This study also provides implications for marketers. Our study shows that credibility perceptions determine the persuasiveness of the SMI. So, when brands and marketers choose an SMI, it seems important to consider the overall self-presentation of the SMI in a post. This study showed that layperson and opinion leadership self-presentation strategies are relatively more persuasive than a micro-celebrity strategy. More specifically, we show that influencers who present themselves as laypersons affect attitudes and buying intentions through trust and social attractiveness. In addition, our findings show that influencers who present themselves as opinion leaders can enhance persuasion through their perceived expertise.

Limitations and future research

Several limitations should be kept in mind when interpreting the results. This study focused on a female influencer and a female target group. More research is needed to examine the robustness of our findings. Among others, our focus on females limits its generalizability to a more diverse population, including men. Prior research showed that men and women respond differently to word-of-mouth (WOM) marketing, such as influencer marketing (Kempf and Palan, 2006).

To be able to cleanly manipulate the influencer’s self-presentation strategy, we chose an influencer that was unknown to our participants. By doing this, we made sure that the participants did not have pre-existing perceptions of the influencer that may have conflicted with our manipulation. However, this also means that our results are based on a single blog exposure. Future research is needed to see how self-presentation strategies that are built in multiple posts affect audience perceptions and persuasion.

Furthermore, future research could investigate whether the current findings are generalizable to other media platforms. Each medium has its own features and technical possibilities. Brivio and Ibarra (2009) showed that social media users choose how they present themselves according to their aims and the technical possibilities of the medium. Consequently, some medium contexts might lend themselves better to certain self-presentation strategies than others and affect followers’ perceptions differently.

Table 1

Means and standard deviations (between parentheses) for the mediators per self-presentation strategy

	Self-presentation strategy
	Layperson	Opinion leader	Micro-celebrity
Trustworthiness†	4.56 (0.91)a	4.33 (1.02)ab	4.24 (1.06)b
Expertise*	4.46 (1.00)a	5.11 (0.99)b	4.80 (1.09)ab
Physical attractiveness	4.74 (0.73)a	4.95 (0.79)a	4.79 (0.87)a
Social attractiveness	3.29 (1.08)a	3.10 (1.13)a	2.99 (0.98)a

Note(s): Different superscripts in a row indicate significant differences between conditions. †p < 0.10 and ^*p < 0.05

Source(s): Created by authors

Table 2

Indirect effects of self-presentation strategies on brand responses

	B	SE	BC 95% CI		H accepted/rejected
			Lower	Upper
H1: Layperson (1) vs micro-celebrity (0) → Trustworthiness → Dependent variable:					H1.i accepted
H1a – Brand attitude	0.15	0.07	0.02	0.31
H1b – Product attitude	0.16	0.08	0.02	0.32
H1c – Purchase intention	0.17	0.08	0.02	0.33
H1: Opinion leader (1) vs micro-celebrity (0) → Trustworthiness → Dependent variable:					H1.ii rejected
H1a – Brand attitude	0.03	0.08	−0.12	0.18
H1b – Product attitude	0.03	0.08	−0.13	0.19
H1c – Purchase intention	0.03	0.09	−0.15	0.20
H2: Opinion leader (1) vs layperson (0) → Expertise → Dependent variables:					H2.i accepted
H2a – Brand attitude	0.26	0.08	0.12	0.44
H2b – Product attitude	0.25	0.08	0.12	0.42
H2c – Purchase intention	0.28	0.09	0.12	0.47
H2: Opinion leader (1) vs micro-celebrity (0) → Expertise → Dependent variable:					H2.ii rejected
H2a – Brand attitude	0.12	0.07	−0.01	0.28
H2b – Product attitude	0.12	0.07	−0.02	0.26
H2c – Purchase intention	0.12	0.08	−0.02	0.28
H3: Micro-celebrity (1) vs layperson (0) → Physical attractiveness → Dependent variable:					H3.i rejected
H3a – Brand attitude	0.02	0.06	−0.10	0.14
H3b – Product attitude	0.02	0.07	−0.11	0.16
H3c – Purchase intention	0.02	0.06	−0.09	0.15
H3: Micro-celebrity (1) vs opinion leader (0) → Physical attractiveness → Dependent variable:					H3.ii rejected
H3a – Brand attitude	−0.07	0.07	−0.21	0.05
H3b – Product attitude	−0.08	0.07	−0.23	0.06
H3c – Purchase intention	0.07	0.06	−0.20	0.05
H4: Layperson (1) vs micro-celebrity (0) → Social attractiveness → Dependent variable:					H4.i accepted
H4a – Brand attitude	0.15	0.07	0.01	0.30
H4b – Product attitude	0.16	0.08	0.02	0.31
H4c – Purchase intention	0.23	0.11	0.02	0.45
H4: Layperson (1) vs opinion leader (0) → Social attractiveness → Dependent variable:					H4.ii rejected
H4a – Brand attitude	0.12	0.08	−0.03	0.27
H4b – Product attitude	0.12	0.08	−0.03	0.28
H4c – Purchase intention	0.18	0.12	−0.05	0.42

Note(s): Unstandardized b-coefficients; BC 95% CI = 95% Bias corrected bootstrap confidence interval using 5,000 bootstrap samples; italics means the indirect effect is significant; N = 229

Source(s): Created by authors

Notes

1. As the product category in this study concerns sports fashion, the perceived physical attractiveness of the endorser is expected to be relevant to the endorsed product.

Data availability statement: The data that support the findings of this study are available from the corresponding author upon reasonable request.

Appendix Stimulus materials

Layperson blog

Hi! My name is [X]. I am 27 years old and I was born and raised in Belgium. I am an athlete and want to keep my body healthy and in shape to get the best performances. Also, I enjoy going to the gym. People could describe me as a typical fitness guru. I hope to inspire others with my fitness blog, in which I share tips on how to stay motivated, eat healthy and get your body in a great shape. Below you can read my most recent blog post.

How to stay motivated during corona times?

I feel like I have been sitting still for too long during this Corona period. Since home quarantine was introduced, I find it difficult to motivate myself to work out frequently. Especially now that the gyms are closed, I need to find alternative ways to work out. It might sound strange, but I lost my inner drive. So, maybe I could say I suck at keeping a good daily quarantine sports routine. That rhymes!

While I normally love working out and going to the gym, this feeling changed during home quarantine. So, I questioned myself about why this feeling changed and found out that I feel a bit lonely during home workouts. I realized I am more motivated to do a fitness class when I am surrounded by other people in the gym. I miss social contacts and get less satisfaction from online classes relative to physical classes. Can you relate to this feeling? Please let me know if you have any suggestions for nice and motivating online classes. I am open to new courses. Of course, I also tried some things myself last week in order to reboot my motivation to work out. I would love to share one funny finding in this blog!

If you encounter difficulties keeping yourself motivated to work out during this Corona crisis, you should consider wearing your workout gear throughout the day. Workout gear is not only very comfortable while working from home during Corona times, but you are also ready for a workout at any time of the day. So, if you feel like it, you can immediately start working out. Did you know that if you combine a nice, good-looking sports outfit, you will directly feel better and be more productive?! I certainly am! Therefore, I thought about sharing my favorite sportswear brand, which keeps me motivated these days!

The brand I am referring to is [X], a high-end brand that combines the high-performance aspect with femininity and cool urban elements. The brand has a strong focus on delicate fabrics in all its designs. Recently, they launched their new line, “Right Tribe,” which is so much more than only athleisure wear. The fashionable, cool and high-end designs ensure that you can effortlessly go from your yoga or bootcamp workout to your Zoom meeting for work and everything in between. [X] is made not only to perform but also to stand out. I love it! Find your fit here.

This blog post is sponsored by [X].

Opinion leader blog

Hi! My name is [X]. I am 27 years old and I was born and raised in Belgium. I am an athlete and want to keep my body healthy and in shape to get the best performances. Also, I enjoy going to the gym. People could describe me as a typical fitness guru. I hope to inspire others with my fitness blog, in which I share tips on how to stay motivated, eat healthy and get your body in a great shape. Below you can read my most recent blog post.

How to stay motivated during corona times?

I often get questions about how I stay motivated to keep working out during this Corona era. Now that the gyms are closed, we need to find alternative ways to do our sports routines. I get emails from people who encounter difficulties motivating themselves to do home workouts because they miss the presence of peer athletes and could use some help. Considering my background as a professional athlete, I would love to share my experiences.

You should know that I have met many people who encounter problems with a lack of motivation to work out. I have been trying to help some of these people find their source of motivation again. Of course, motivation varies extremely per individual, but I saw this as a personal challenge and did lots of research on factors that enhance or discourage motivation to work out. Maybe it is nice to know; I recently got interviewed on this topic as well. It was an interview for a sports channel on television, for which I will share the link in my next blogpost. I also tried some things myself in order to find out what triggers me personally to work out during these Corona times. Below, I will share one of my favorite recommendations with you!

If you encounter difficulties keeping yourself motivated to work out during this Corona crisis, you should consider wearing your workout gear throughout the day. Workout gear is not only very comfortable while working from home during Corona times, you are also ready for a workout at any time of the day. So, if you feel like it, but you can directly start working out. Did you know that if you combine a nice, good looking sports outfit, you will directly feel better and be more productive?! I certainly am! Therefore, I thought about sharing my favorite sportswear brand, which keeps me motivated these days!

The brand I am referring to is [X], a high-end brand that combines the high-performance aspect with femininity and cool urban elements. The brand has a strong focus on delicate fabrics in all its designs. Recently, they launched their new line “Right Tribe,” which is so much more than only athleisure wear. The fashionable, cool and high-end designs ensure that you can effortlessly go from your yoga or bootcamp workout to your Zoom meeting for work and everything in between. [X] is made not only to perform but also to stand out. I love it! Find your fit here.

This blog post is sponsored by [X].

Micro celebrity blog

Hi! My name is [X]. I am 27 years old and I was born and raised in Belgium. I am an athlete and want to keep my body healthy and in shape to get the best performances. Also, I enjoy going to the gym. People could describe me as a typical fitness guru. I hope to inspire others with my fitness blog, in which I share tips on how to stay motivated, eat healthy and get your body in a great shape. Below you can read my most recent blog post.

How to stay motivated during corona times?

I require myself to be in my best shape and eat healthy, even during these Corona times. Now that the gyms are closed, I need to search for alternative ways to do my sports routines. Fortunately, I love getting up early for a nice morning run. So, since the moment home quarantine was introduced, I have not encountered any difficulties motivating myself to work out frequently. I would love to share my secret with you.

Yesterday I woke up early and was looking forward to a good workout session. So, I went to my basement, where I have a beautiful personal gym. I have a lot of fitness equipment and materials in the basement. This equipment is super helpful to keep my condition up! Also, my daily results are tracked, which motivates me to keep up the good work. After warming up, I called in with my friend Mary Helen Bowers. She is a personal trainer who trained, among others, Natalie Portman for her role in the film “Black Swan”. Impressive, right? Training together makes it so much easier to stay motivated. If you don’t have a fitness buddy to work out with, I might have a simple trick for you, which helps me personally stay motivated during the day.

If you encounter difficulties keeping yourself motivated to work out during this Corona crisis, you should consider wearing your workout gear throughout the day. Workout gear is not only very comfortable while working from home during Corona times, but you are also ready for a workout at any time of the day. So, if you feel like it, you can immediately start working out. Did you know that if you combine a nice, good-looking sports outfit, you will directly feel better and be more productive?! I certainly am! Therefore, I thought about sharing my favorite sportswear brand, which keeps me motivated these days!

The brand I am referring to is [X], a high-end brand that combines the high-performance aspect with femininity and cool urban elements. The brand has a strong focus on delicate fabrics in all its designs. Recently, they launched their new line, “Right Tribe,” which is so much more than only athleisure wear. The fashionable, cool and high-end designs ensure that you can effortlessly go from your yoga or bootcamp workout to your Zoom meeting for work and everything in between. [X] is made not only to perform but also to stand out. I love it! Find your fit here.

This blog post is sponsored by [X].

Note(s): Pictures blurred because of copyrights

Source(s): All blogs created by authors