The researchers utilize social identity theory to investigate the effect that athlete endorsers have on both brand and team-related attitudes and intentions. As fans identify more strongly with an athlete, the more they intend to purchase the endorsed products. Additionally, a fan’s level of identification with an athlete is positively transferred to their attitude toward the team. The influence of athlete ID on team abandonment was fully mediated through attitude toward the team. However, fans who identified less with the athlete endorser were more likely to abandon the team’s market offerings than those fans who identified more with the athlete endorser. Athletes endorse products more often than any other celebrity category (i.e., musicians, actors, comedians, etc). While 20 percent of all ads feature a celebrity, approximately 60 percent of celebrity endorsed advertisements feature an athlete, thus demonstrating the dominance of athletes as endorsers (Dyson & Turco, 1998). Furthermore, nearly 10 percent of advertising costs is spent on fees to these endorsers. Companies are willing to invest millions of dollars to associate their brand names with easily recognizable athletes. For example, more than $12 billion is spent on multiyear athlete endorsements by corporations with more than $1.6 billion committed by Nike alone (Horrow, 2007, 2005). Some professional athletes make more money annually from endorsement deals than from salaries. The top ten sport endorsers of 2006 were paid a combined $223 million (Freedman, 2007). Tiger Woods, alone, earned $87 million from endorsement deals in 2006 and has multi-year endorsement contracts of $105 million and $40 million with Nike and Buick, respectively (DiCarlo, 2004). Since Tiger Woods signed with Nike, annual sales for Nike Golf have grown to nearly $500 million with an estimated 24 percent per year growth in the first five years of the agreement (Pike, 2006). While endorsements from celebrities such as Tiger Woods have a positive impact on product evaluations, the impact of such endorsements on the athlete’s sport affiliation (e.g., the PGA for Tiger Woods; the Indianapolis Colts for Peyton Manning) has been unexplored. This study contributes to research on athlete endorsers by implementing a social identity theory framework and empirically evaluating the impact of fans’ identification with athlete endorsers on both brand and team-related outcomes. In a field study with 494 subjects, we tested a model that indicates that athlete identification influences brand purchase intentions and attitude toward the team, which thereafter influences team abandonment. We discuss our findings and provide suggestions for team and brand managers to improve endorsement-related decision making.