How are fans affected by the commercialization of elite sports? A review of the literature and a research agenda

Purpose – The purpose of this paper is to develop a holistic understanding of extant studies addressing the impact of commercialization on fans of elite sports. Design/methodology/approach – In doing this, the authors performed a structured review of 42 academic articles published between 1992 and 2020 that all focus on how fans respond and are affected by the commercialization of elite sports. Findings – Thestructuredreview showsthat the impactsof commercialization onfans relate tofour different themes. These are (1) fan identity, (2) fan attitudes, (3) fan emotions and (4) fan behaviours. However, the analysis also shows that research within each category is largely scattered, and more research within each category is needed. Originality/value – Thepaperhighlightsthecomplexanddynamicnatureofcommercialization.Itpresentsa research agenda for future research and emphasizes a need to integrate the interests of several stakeholders when managing the impacts of elite sport commercialization.


Introduction
Elite sports have been subject to commercialization for many decades (Dubal, 2010;Hoehn and Szymanski, 1999). Commercialization is increasingly evident in many elite sports service ecosystems (e.g. Merkel et al., 2016;Laurell and Soderman, 2018) and is at least partly induced by sponsors (e.g. Woisetschl€ ager et al., 2013), new types of ownership structures (e.g. Mason, 1999), major broadcasting contracts (e.g. Merkel, 2012), and the pursuit of teams to engage with more fans (e.g. Numerato and Giulianotti, 2018). Thus, commercialization can spur opportunities for teams and, or athletes to earn more profits and therein, to become more successful.
However, commercialization may also encounter severe resistance in elite sports service ecosystems. The failed attempts by club owners to start a European "Super League" in football [1] (Panja and Smith, 2021) and the debates of whether to allow sponsorship within College Sports in the USA (Zhang et al., 2005) are two examples when commercialization has been heavily criticized. Fans, i.e. individuals with a psychological connection to one or several team(s), sport(s), and/or athlete(s) (Funk and James, 2001), are important actors in this regard. Their money, time and passion are the cornerstones for this intensified commercialization.
Several examples highlight that many fans are sceptical of the increasing commercialization of the elite sports service ecosystem (Numerato and Giulianotti, 2018;Woisetschl€ ager et al., 2013). For instance, fans may witness how their favourite teams cooperate with new sponsors, create new engagement platforms, or raise ticket prices to ensure revenues (Thani and Heenan, 2017). These changes may negatively affect fans' engagement with and perceived value of being fans (Tinson et al., 2021;Hognestad, 2015). In some contexts, fans may also perceive their sport, team, or athlete to be taken over by commercial ideals, which shifts the roles of fans to more passive consumers (e.g. Numerato and Giulianotti, 2018). Noticeable reactions by fans in response to increased commercialization may be protests against their clubs (Merkel, 2012), as shown with the European Super League (Panja and Smith, 2021), and some fans may even abandon their team and, or sport (Giulianotti, 2002). However, some research indicates that fans may also perceive commercialization as a positive process. Sometimes, commercial revenues are, for example, one reason why teams or athletes improve their possibilities of winning (Abosag et al., 2012).
As indicated, the service ecosystems of elite sports are increasingly influenced by commercialization (Laurell and Soderman, 2018). Several studies are discussing this intensified commercialization in general and its consequences for fans (e.g. Dixon, 2014;Kennedy, 2012). However, to date, no structured review has been published on this topic. This study therefore aims to address this knowledge gap in the nexus between increased commercialization, elite sports, and the impacts on fans. Therefore, the purpose of this review is to develop a holistic understanding of extant studies addressing the impacts of elite sport commercialization on fans.
The review contributes with an analysis of studies and an agenda for future research, focusing on how fans are affected by-and respond to-increasing commercialization. The findings are important for both scholars and practitioners as commercialization has been heavily debated among fans, media, and clubs, and as it is only in recent decades that scholarly attention has focused upon this topic.

Literature review Fans
Fans are defined as individuals with a psychological connection and specific interest in one or several sports, teams, and/or athletes (Funk and James, 2001). As fans spend time, resources, and money on activities and apparel related to a team or sport, fans are sometimes, in commercial settings, regarded as customers of elite sports (Giulianotti, 2002). However, fans may not consider themselves to be customers as their levels of engagement and loyalty to their teams often are very distinct from traditional relationships between a customer and a firm (Numerato and Giulianotti, 2018). It is also important to note that fans are not a homogenous group (Wang et al., 2020). For instance, different levels of loyalty (Dwyer, 2011), engagement (Yoshida et al., 2014), identification (Wann and Branscombe, 1990) and roles in value-co-creation exist (e.g. Horbel et al., 2016;Uhrich, 2014).

The nature of commercialization
Here, commercialization is defined as the prioritization of financial revenues among organizations and actors, such as teams, athletes and or sponsors in elite sports service ecosystems (e.g. Fritz et al., 2017). It is a multifaceted process which may take on many different forms. Apart from commercialization of elite sports, studies have as well examined its impacts on tourism (Swanson and Timothy, 2012), music (Moore, 2005) and to cultural customs (Belk, 1987). In the previous literature, other concepts are often interlinked to commercialization of elite sports, such as commodification, marketization, modernization and globalization. Commodification is closely related to commercialization and is often used to describe that in a process where commercial gains are increasingly prioritized, people, A review of the literature on elite sports services, ideas, and objects, such as sports teams and fans, become commodities with market values (Numerato and Giulianotti, 2018). Marketization of elite sports is also like commercialization, as it describes how elite sports take the shape of a market economy, where clubs operate as businesses, and fans as customers (Liang, 2017). In addition, modernization and globalization are often related to commercialization, as they highlight that a commercial logic motivates organizations and other actors to modernize and globalize to gain financial revenues (Backman and Carlsson, 2020). All the above-mentioned concepts refer to how financial ideals become more important to organizations and actors intertwined in the service ecosystems of elite sports. Commercialization of elite sports. In elite sports, commercialization implies a focus on market-oriented ideals, business-like management structures and sponsorship activities (Dubal, 2010). For some fans, this focus may imply tensions and conflicts with their own ideals and perceptions of authenticity (e.g. Fritz et al., 2017). As with other service ecosystems, commercialization varies depending on factors such as geographical context, the sport itself, and the way the sport is practised. In some sports, such as franchise-driven American elite sports leagues, professional boxing, professional cycling and Formula One, commercial ideals and structures have been present for a long time. Hence, the conflicts and tensions between a commercial, and a non-commercial logic are not equally intense as in, e.g. European elite football (Numerato and Giulianotti, 2018). In European contexts and in a competition like the Olympics, elite sports often have close associations to ideals of amateurship and local connectedness. Therefore, ideals related to this heritage may be prone to collide with intensified commercialization (Numerato and Giulianotti, 2018). Table 1 provides a detailed list of activities and processes that exemplify intensified commercialization and how it impacts different elite sports.

Method
To understand how commercialization affects fans of elite sports, we perform a structured review. Methodologically, the review builds on the method suggested by Tranfield et al. (2003) comprising three main stages: planning, conducting, and reporting. Such a structured procedure increases the validity and reliability of the study (Snyder, 2019). This as the standardized design, process and analysis reduces biases and errors in the review process (Snyder, 2019). It is exemplified in this review process by the strict criteria for including papers that explicitly addressed the impacts of commercialization on fans.
The planning phase focuses on assessing the relevance and limits of the specified topic. For this review, commercialization, fans, and elite sports are the main concepts. Commercialization is defined as the process of subordinating traditional values and norms in favour of profit maximization (Fritz et al., 2017). Second, fans are viewed as individuals with a psychological connection to a sport, a team and, or an athlete (Funk and James, 2001). Third, elite sports are regarded as sports performed on the highest athletic level.
The second stage of the review process, i.e. conducting the review, aims to ensure a valid search process. This implies a process that remains strict to the scope, as well as to the relevance of the paper (Tranfield et al., 2003). Thus, it is important to include a variety of databases to obtain a valid foundation for analysis (Tranfield et al., 2003). For this review, we used the following eight databases: Academic Search Complete, BusinessSource Premier, Google Scholar, JSTOR, PsycINFO, Scopus, CABI Leisure Tourism and SportDiscuss. The six former databases contain a wide scope of articles, and the two latter databases specialize in elite sports and leisure research. "Sport" was the principal keyword, combined with "Commercialization". To extend the scope of the search, we, based on an overview of related papers found in the preliminary stages of this review and the literature review on the concept of commercialization, included the following terms: "Commodification", "Marketization", "Modernization" and "Globalization". As explained above, they are often connected and used as dimensions of commercialization (Numerato and Giulianotti, 2018). For fans, we used the following terms: "Fans", "Consumers" and "Supporters". This procedure yielded 84 articles whose abstracts matched the scope of the review. We thereafter extended the search to academic journals explicitly focusing on sports and elite sport management, i.e. European Sport Management Quarterly, International Journal of Sport and Society, Sport Management Review, Journal of Sport and Tourism, and Sport Marketing Quarterly, Sport, Business and Management: An International Journal. This yielded 42 additional articles. As a final stage, we assessed leading marketing journals, with an explicit perspective on individuals as customers. The journals included for this stage were In total, 134 articles were retrieved. However, as Snyder (2019) suggests, it is important to consider excluding articles that, based on a detailed evaluation, do not meet the scope of the review to make the review more trustworthy. Hence, papers with little relevance and/or only a minor focus on the impacts of commercialization on fans of elite sports were excluded. Twentyone articles included commercial elite sports as a fixed context in studying fan identification and the identity of fan communities. As they did not focus on how the process of commercialization affects fans, they were excluded. There were also articles covering general sport-related issues, such as the governance of the Olympics, which only briefly mentions fans. Subsequently, having evaluated the papers on a more detailed level, we arrived at a list of 42 relevant articles.
For the final stage of the review, i.e. reporting the results, a suitable approach is to categorize the reviewed literature (Tranfield et al., 2003). Following this principle, we categorized the papers based on (1) year of publication, (2) author, (3) journal, (4) method, (5) geographical context, (6) type of elite sport, (7) theoretical framework, (8) empirical results and (9) effects on fans of commercialization. We then analysed the content and findings to perform a relevant thematic analysis. The resulting themes emerged without any specific analytical or theoretical model and set the basis for the analysis and research agenda.

Results
The results are organized according to (1) methodological applications, (2) studied contexts and (3) the theoretical nature of the reviewed articles. Thereafter, analytical themes for how elite sport commercialization affects fans and how fans respond are presented.
Methodological, empirical, and theoretical nature of the research A categorization of the reviewed articles is important to provide an overview of the topic (Tranfield et al., 2003). articles are based on qualitative research methodology (18 articles). In addition, surveys are the most used method for collecting data (11 articles). We then categorized the papers based on empirical contexts: the type of sport studied, the geographical focus, and the gender balance (Table 3). Almost all articles (34 of 42 papers) focus on commercialization in the context of elite football. Anglo-Saxon regions, particularly England (14), were the most prominent. In all, the European focus is noteworthy and as only nine of 42 papers are outside Europe it seems as, the issues regarding commercialization of elite sports seem to be the most intense within Europe. Essentially, all papers focused on sports for men, and there was no article studying fans in women's elite sports.
Regarding the theoretical frameworks applied, many papers did not use one overarching theoretical framework. Thus, Table 4 is a combination of theoretical frameworks as well as theoretically oriented concepts. There is a dominance of papers applying identity theory and social identity theory (15 papers), highlighting the importance of fandom to self-identity construction. There is an inclination towards critical perspectives and critical theorization (10 papers) focusing on commercialization and its negative impacts on fans. The third most applied theoretical framework is cultural theory.

Analytical themes
Each paper was summarized to review how fans are affected by an increasing commercialization. This yielded four major themes: (1) Fan Identity, (2)   studies sometimes focus on "more than" one of the consequences for fans. Table 5 summarizes each theme and the major results found in the specific papers.
How commercialization affects the identity of fans. Regarding identity, the studies highlight that commercialization can contribute to making fan identities globalized. While fans and other major stakeholders traditionally have been local, teams and athletes increasingly seek to internationalize their fan bases to expand commercially (e.g. Kerr and Emery, 2011). Furthermore, Giulianotti (2002) argues that commercialization changes fans' identities and roles from a "hot, traditional identification with local clubs" to a "detached, cool, consumer-orientated identification" (p. 25). While local culture, norms, and history may still play a role, Petersen-Wagner (2017) argues that commercialization drives an individualization of fans. This implies that fans increasingly construct their self-identities using commercial elements that best fit their own desire, in contrast to previously more community-oriented self-identification (Petersen-Wagner, 2017).
Commercialization contributes to tensions between the local and the global, for instance, between fans and local teams, and fans and foreign teams living in the same area (Evans and Norcliffe, 2016). The tension between the local and distant fans is also stressed by Evans and Norcliffe (2016), who illustrate that local fans may repel the commercialization of fan identities. This is because these "tourist fans" have not been loyal to the teams for long.
Several studies also indicate that commercialization affects how, and through what interactions fans develop their personal identity with the team or the sport (e.g. Hoegele et al., 2014;Meng et al., 2015). Examples of changed structures for fan identification are, for instance, the growth of global superstars, which for some are more important to the identity than the team (Hoegele et al., 2014). In addition, new sponsors may be perceived as a threat to   (2008) argue, through an observational study of fan parks at the FIFA World Cup 2006, that sponsor-organized environments may transfer the control of creating fan identities from fans to other actors (e.g. sponsors). On the same topic, Delia (2017) studied fan identities in the service ecosystem of cycling and found that long-term sponsorship may result in positive "legacy effects". Thus, in some contexts, such as cycling, where sponsors are intimately connected to the team, fans may identify with the sponsor and even do so after the commercial agreements are terminated (Delia, 2017).
How commercialization affects the attitudes of fans. Attitudes are fans' overall evaluation of an object, issue or person (Parganas et al., 2017). In an elite sport context, the attitude object can range from an individual athlete to a team, league, or sport.
Sponsorship has been extensively researched in relation to fans' attitudes. Sponsorship can have both positive and negative effects on fan attitudes towards teams and sponsors (e.g. Jensen et al., 2012;Dos Santos et al., 2016). Chanavat and Bodet (2014) ) illustrate that as sponsors increase in numbers, it is important for the sponsoring brand to match its brand identity with the team identity. Additionally, instead of focusing on attitudes towards the team or athlete, Parganas et al. (2017) surveyed how sponsorship can affect attitudes and purchase intentions in relation to the sponsoring brand. They found that if fans identify strongly with a team, it reduces the likelihood that fans switch to a competitive brand (Parganas et al., 2017).
Another aspect of commercialization revolves around the ownership structures of teams. In many contexts, especially within elite football, there is an increasing tendency of clubs being bought by private investors to earn money or for clubs to become marketing platforms for owners. However, some contexts are quite different. Bauers et al. (2019) studied German football fans' attitudes towards selling more than 50% of clubs to private investors. The study indicates that most fans do not want this privatization development for two reasons: to prevent commercial interests in more than one club and for reasons of traditional and social interest. The results also imply that most fans, at least in Germany, do not support what is seen as a significant involvement of private actors (Bauers et al., 2019). Thus, changing regulations in club ownership may negatively affect fan attitudes.
Finally, attitudes among fans have also been studied in relation to the increased tensions between the local and global that commercialization contributes to. Behrens and Uhrich (2019) emphasize that commercialization has increased the presence of foreign fans, so-called "satellite fans". Studying Spanish and German football fans, Behrens and Uhrich (2019) observed that fans may be sceptical of newcomers. However, if "satellite fans" understand and adapt to the existing local fan community, positive attitudes towards this group are more likely.
How commercialization affects the emotions of fans. The third theme that emerged in the review relates to the impacts of commercialization on fan emotions, for instance, the intensity of anger, anxiety, dejection, happiness, and excitement as responses to certain stimuli in the elite sport context (Biscaia et al., 2012).
One main site that elicits fan emotions is the arena. According to commercial ideals, having a modern stadium is deemed fundamental. Ritzer and Stillman (2001) study the modernization of baseball stadiums and how this affects fan emotions. They argue that stadiums that are overly rationalized, "McDonaldized", and unauthentic can reduce the A review of the literature on elite sports emotional dimensions embedded in stadiums, thus weakening emotional intensity (Ritzer and Stillman, 2001). Uhrich and Benkenstein (2012) surveyed German football fans and show how fans and their behaviours remain fundamental for evoking fan emotions. The authors illustrate five dimensions generating emotions among fans in stadiums: customers' density, customers' appearance, customer behaviours, arena ambiance and arena design (Uhrich and Benkenstein, 2012). Thus, as stadiums increasingly contain commercial elements and become more convenient stages for sport consumption and to experience the sport, social aspects cannot be underestimated (Uhrich and Benkenstein, 2012). Abosag et al. (2012) study clubs from a branding perspective and focus on the implications of commercial brand extensions on fans' emotions. Fleischmann and Fleischmann (2019) find that through social media, domestic fans more easily bond emotionally with their teams. These types of brand extensions are discussed as sports organizations' activities going beyond the core product of the team to generate more revenues, for example, marketing branded merchandise to extend the fan experience (Abosag et al., 2012). For some fans, brand extensions and other potential ways to increase revenues can deepen fans' emotionally derived involvement with a club (Abosag et al., 2012).
Another line of research focuses on how commercial elements are used to elicit emotions among fans, for instance, by drawing upon nostalgia. Andon and Houck (2011) study fan emotions in relation to the NHL Winter Classic, a special and commercial sporting event. The authors find that the nostalgic cues used in this event are a means to yield excitement and evoke more emotions (Andon and Houck, 2011). The findings suggest that by commercializing, e.g. the heritage of the sport or the team, fan emotions can be intensified.
How commercialization affects the behaviours of fans. The final theme that emerged in the review focuses on fan behaviours. Two main subareas identified within this theme are fan loyalty and fan resistance. Regarding fan loyalty, several studies indicate that the commercialization of elite sports can affect the loyalty of fans. Fan loyalty is conceptualized into two main dimensions, i.e. psychological and behavioural loyalty (Bauer et al., 2008). Loyalty thus refers to both the psychological connection and intention to remain a fan to a team, as well as the behavioural aspects of being a fan, such as if and to what extent the fan attends games (Bauer et al., 2008).
Four papers explicitly touched upon fan loyalty in connection to commercialization. While it is difficult to generalize from the four papers, most arguments discuss the negative impacts of commercialization on fan loyalty. For instance, in a study on former fans of NHL teams, commercialization is brought up as a reason for the de-escalation of fandom (Hyatt and Foster, 2015). Participants in the study give word to the notion that "overcommercialization" can lead to disenchantment and thus erode fan loyalty (Hyatt and Foster, 2015). Hognestad (2012) highlights the notion that increasing commercialization in combination with increasing media interest has the tendency to move fans from being supporters of one club (so called "mono-supporters") to several. Having split loyalties, Hognestad (2012) argues that Norwegian fans can have favourite clubs both locally and in other leagues (so-called "poly-supporter"). In an ethnographic study of an English premier league team, Putra (2019) highlights that the commercialization of the club, the possibility of selling tickets to foreign fans, and increasing ticket prices can potentially reduce loyalty among local fans. There is a risk that the loyalty of "poly supporters" (Hognestad, 2012) and "satellite fans" (Behrens and Uhrich, 2019) could come at the cost of lost loyalty among local fans. Dixon (2014) interviewed loyal, long-term English football fans regarding the so-called "Disneyfication" of products, services and experiences that are branded and sold using their team's logo. In most cases, however, the interviewees saw this increased emphasis on branding and club merchandise as something exciting and contributing to the experience of being a fan.
Some studies also highlight that commercialization can spark fan resistance. Resistance, described as "a strategy of appropriation in response to the structures of domination" SBM 13,1 (Woisetschl€ ager et al., 2013(Woisetschl€ ager et al., , p. 1490, is often a central topic in critical papers (see, e.g. Giulianotti, 2011). Several studies share the view that fan resistance develops when commercialization leads to perceived alienation (Duke, 2002;Hewer et al., 2017). Here, commercialization threatens fans' existing involvement with the sport entity (e.g. Woisetschl€ ager et al., 2013). Furthermore, resistance may be evoked due to commercial influences on existing traditions and rituals (Hognestad, 2015). For instance, new ways of organizing events and organizing a fan community can form a perceived disenchantment and over-rationalization that fans resist (Hognestad, 2012).
Several papers address how resistance to commercialization is manifested among fans. Fan resistance can motivate fan communities to reshape the meanings and identities of clubs (e.g. Daniel and Kassimeris, 2013;Torchia, 2016;Totten, 2016). An extreme example is how fans' resistance to commercialization of a football club (in this study, Manchester United) can result in fans creating a new club (FC United of Manchester), based on former traditions and values (Torchia, 2016).
Commercialization and possible fan resistance may not always imply negative consequences on the relationship between teams and fans (e.g. Dubal, 2010). Nash (2000) finds that, as major leagues, such as the English Premier League commercialize, it can increase the willingness of and opportunities for fans to engage with club management. Additionally, Dubal (2010) recognizes the rise of tensions regarding modern football adopting market-based structures. Dubal (2010) illustrates that these frictions can open up fans to increase their influence through, for instance, uniting in fan communities. Additionally, Merkel (2012) studied German football fans and found that commercialization and resistance among fans can motivate a higher degree of fan involvement.

Analysis and future research agenda
This review set out to investigate how research has studied how fans are affected by intensified commercialization. Through a structured review of current research, several insights have been presented. In the following sections, we analyse the state of research and present a research agenda to serve future studies.

Summary and analysis
At this stage, at least three important observations about the literature can be drawn: (1) The literature has often highlighted that commercialization has negative consequences for fans.
(2) The literature has mainly derived conclusions from European elite football contexts.
(3) It is difficult to come to a clear-cut conclusion for how fans respond to increasing commercialization. Instead, responses differ depending on aspect(s) of commercialization, geographical context(s) and the outcome variable(s) studied.

Diversity of commercialization.
As shown in this review, commercialization is not unidimensional. Instead, the reviewed papers show the many different aspects of commercialization, such as sponsorship, business-like management, and modernization of stadiums. As elite sports are often characterized by close bonds between fans and teams or athletes, the different dimensions of commercialization impact this relationship. For instance, if clubs prioritize financial profits, fans may respond negatively to the fact that they are treated as regular customers. However, commercialization, such as more revenues from sponsors, increases the possibilities of recruiting better players or modernizing club facilities that may be embraced by fans. Table 6 highlights aspects of commercialization found in the review, as well as the main conclusions reached in the studies on how fans respond to commercialization.

A review of the literature on elite sports
Disparities across outcome variables. The varying implications for fans are also present when looking at the main outcome variables. As Table 7 pinpoints, the negative consequences of elite sport commercialization for fans are more prevalent in connection to fan behaviours. These studies focus, for instance, on how fans may respond to commercialization by resisting these influences. Studies on fan identity, attitudes and emotions portray more varying effects. For instance, Delia (2017) illustrates, in the context of cycling, that sponsors may be perceived as a crucial and beneficiary element of an elite sport team and to the fan's identification with the teams.
Methodological diversity. Another reason for the difficulties in finding clear consensus is the variety of applied methods. While different methodological perspectives are generally positive, the results show that conceptual studies, and to a certain extent qualitative studies, seem to be more focused on the negative effects on fans (Table 8). Many conceptual studies apply critical theory and, as such, perhaps a built-in critical perspective towards increasing commercialization. Quantitative papers, on the other hand, often find both positive and negative responses among fans.
Geographical diversity. The geographical areas of the studies provide many different results on how fans are affected by commercialization (Table 9)  setting, i.e. English elite football, commercialization is mainly associated with negative effects for fans. Here, commercialization is studied as a process that moves away from, and causes conflicts to traditions and the local connectedness (Duke, 2002). Still in a European context, more specifically German elite football, studies have provided more nuanced understanding to commercialization as both negative and positive responses have been presented, e.g. commercialization has promoted a democratic transformation of fan involvement (Bauers et al., 2019). However, as research on commercialization is remarkably scarce outside Europe, for instance in North America and, or Asia, it indicates that commercialization may not cause the same types of tensions and resistance in these contexts as in Europe. Tables 6-9 have, at least, one thing in common; negative effects on, and negative responses of, fans dominate. Thus, is it fair to conclude that fans respond to and are affected negatively by an increasing commercialization of elite sports? At this stage of the field's early maturity (42 papers in this review), we do not know for sure. It is too early to say. Indeed, as shown in the tables above, there seems to be signs that research using certain methodologies and that takes place in certain cultural contexts (Europe) finds mainly negative responses among fans. Further research is needed that embraces the inclusion of a more diverse set of methods, empirical contexts, theories, concepts, and aspects of commercialization. Below, we set out a research agenda focusing on methodological, theoretical, conceptual, and empirical development.

Agenda for further research
Methodological development. Qualitative approaches are dominant in previous literature (18 of 42 papers), and several papers (11) are conceptually written. This is in accordance with research, which highlights that as fields or subfields develop, the first stages are often dominated by conceptual and qualitative studies (e.g. Granados et al., 2011). However, there is a general shortage of quantitative studies to test the specified relationships on larger samples. Developing the quantitative stream can, for instance, measure attitudes and emotions and how commercialization of elite sport influences these. Furthermore, quantitative studies open for assessing different types of fans (from highly involved to more occasionally involved fans) and how these fans embrace and, or resist commercialization. As qualitative studies seem more negative than quantitative, this may also change the view of commercialization as primarily negative for fans.  This review also illustrates methods for studying online contexts are scarce (see Table 2). Social media is an increasingly important platform for consumers and for brand-consumer interactions (Stieglitz et al., 2014), as well as for fan-to-fan and fan-to-team interactions (Wakefield and Bennett, 2018). Therefore, future research should apply methods utilizing these platforms, such as social media analytics (Stieglitz et al., 2014), to investigate how fan engagement on social media is affected by commercialization.
Theoretical and conceptual development. Several of the reviewed papers are written with a theoretical foundation in either identity theories (e.g. Woisetschl€ ager et al., 2013) or critical theory. These papers often use critical approaches to commercialization, regularly using concepts such as commodification (e.g. Merkel, 2012;Numerato and Giulianotti, 2018). Given the multifaceted nature of elite sports commercialization, more research is needed using other theoretical and conceptual approaches, such as consumer psychology, consumer behaviour and stakeholder theory, which have already been applied with interesting outcomes (see Table 4).
Furthermore, there is a shortage of studies discussing the potential positive impacts of commercialization on fans. While critical theory generates interesting results, we advocate for more studies with theorization that can provide perspectives on how fans respond to and are affected by commercialization. Considering the multitude of sports, types of fans and geographical contexts, future studies are likely to find more examples of how commercialization positively influences dimensions of being a fan by using a larger variety of theories and concepts.
We identified four outcome variables in our review: Fan Identity, Fan Attitudes, Fan Emotions and Fan Behaviours. These are well-known research themes in the fan literature (see the eight dimensions proposed by Stewart et al. (2003)). Yet, some themes have received considerably more attention than others. For instance, 16 articles are related to impacts on Fan Behaviours, while only 4 articles deal with impacts on Fan Emotions. This skewness mirrors the emerging nature of this research stream and emphasizes that several themes require more studies.
Empirical development. The analysis highlights the multifaceted nature of commercialization and how the different aspects of commercialization generate varying results (see Table 7). Thus, we encourage future studies to cover a wide variety of aspects to better comprehend the connection between commercialization and fans.
Our review illustrates that the effects on fans of elite sport commercialization have mainly been studied in men's elite football, especially in English top-division contexts (14 of 42 papers are related to the English Premier League). Therefore, in line with Garc ıa and Welford (2015), future research must delve into other types of elite sports and other geographical settings to understand how commercialization affects fans to elite sports. For example, new leagues are created in, e.g. cricket (Khondker and Robertson, 2018) and women's elite football (Valenti et al., 2019). This development supports financial growth and, e.g. international player recruitment, which fans may perceive differently compared to how intensified commercialization is perceived in men's elite football. Some studies have been conducted on these sports and on commercialization; however, they have not explicitly targeted how commercialization affects fans (e.g. Khondker and Robertson, 2018). While more research is needed on fans to other team sports, focusing on more individualized elite sports, such as motor sports, tennis, golf and athletics, can also make substantial contributions to the literature, as they represent sports with other types of fan communities and traditions.
In terms of geographical areas, many European contexts have a different history, and way of commercializing than England. In some countries, the influence of fans over their clubs is institutionalized in laws that restrict clubs from being governed solely by private investors (e.g. Germany (Merkel, 2012;Merkel et al., 2016) or Sweden (Fahl en and Stenling, 2016)). These contexts provide interesting examples where fans might have a greater influence on how commercialization of elite sports should develop. Additionally, the lack of papers in other geographical contexts, distant from Europe, is also striking when assessing the geographical homogeneity of the reviewed papers. Thus, studying other contexts with different background and traditions of sport is important to gain an holistic understanding of commercialization.
Finally, there is a complete lack of studies on the commercialization of women's elite sports and its impacts on its fans in this review (Table 3). This should be addressed given the rapid increase in commercial influences in women's elite sports (Meier and von Uechtriz, 2020;Mumcu et al., 2016). Thus, there is an urgency in approaching fans of women's elite sports and discussing how they respond to commercialization. Also here it is important to move beyond the European borders and for instance examine how, e.g. fans of teams in WNBA and, or tennis players in WTA respond to increasing commercialization. As there are increasing possibilities for female athletes to become professional, commercialization may be seen as something positive by the growing community of fans to women's elite sports.

Conclusions
This paper highlights that commercialization is a complex and multifaceted process that affects the service ecosystems of elite sports and its fans. On an overarching level, the results indicate that increasing commercialization can lead to both value-co-creation and value-codestruction in these service ecosystems. The effects of elite sport commercialization have attracted increased attention from scholars, but as this review has shown, it is still in a rather early stage of maturity and is dominated by conceptual and qualitative studies.
This review also concludes that as many studies are based in Anglo-Saxon contexts, we lack a holistic understanding of the nature of commercialization of elite sports. Several of the studies set in English elite football point out the negative effects of intensified commercialization. Yet, considering the scarcity of papers examining the effects of elite sport commercialization in other contexts, it is important to broaden the contextual applications and conceptual breadth.
Finally, this review indicates that commercialization poses a threat to fans as it may affect many aspects of being a fan. There are several aspects of commercialization that may impinge on the authenticity of a team and the role of fans. However, as pointed out in this review, several aspects of intensified commercialization may also lead to positive responses and effects on fans. From a management perspective, the review stresses the importance of being cautious in, e.g. signing new sponsors, building new arenas, and setting up a strategy to communicate with fans.

Limitations
For this paper, issues relating to degrees of subjectivity and bias must be addressed. First, the choice of explicitly focusing on how commercialization affects fans of elite sports implies that papers that do not have this explicit aim are not included. Hence, papers that discuss commercialization and elite sports in broader terms were excluded from the review.
A review of the literature on elite sports