Despite the growing popularity of professional baseball in South Korea, academic literature lacks much quantitative analysis of its fans. The main purposes of this current study were two-fold. Firstly, it was to identify if fan attitudes and expenditures are associated with and different by demographic variables. Secondly, it was to find out if fan attitudes and expenditure positively predict and explain the variance of future propensity to spend on products and service. A total of 1612 fans who attended Korean baseball games voluntarily participated in this study. The survey questionnaire consists of five sections of demographics information, sport fandom, satisfaction of social media service, satisfaction of the baseball stadium, and future propensity to spend on products and service at the ballparks. An exploratory analysis found that fan attitudes and expenditures differed by demographic variables (e.g., gender, education, age). Second, fan attitudes about the baseball team, satisfaction with baseball stadium, satisfaction with team media social media services, and current venue expenditures proved to bepositive predictors of future propensity to spend on team products and service (FPSPS).