Recent service marketing literature has been focusing attention on service customers as a means of enhancing the competitiveness of service organizations. In particular, since service customers can be recognized as partial employees, customers can exhibit citizenship behavior toward service organizations, through which service organizations can enhance their competitiveness without additional costs. In Study 1, focusing on the exchange relationship between service organizations and customers, customer commitment, perceived customer support, and customer identification were proposed as antecedent variables of customer citizenship behavior, and for perceived customer support in particular, rewards, perceived fairness, and autonomy were additionally proposed as antecedent variables. The empirical analysis using university students as subjects found that seven out of eight hypotheses were supported, demonstrating that service organizations must actively manage service customers in the same manner as they manage employees. Furthermore, through Study 2, this research tested whether the experience attributes of service customers have differential effects on the antecedent variables of customer citizenship behavior. The analysis results confirmed that in the high-experience group, the antecedent variables had a stronger influence on customer citizenship behavior. Therefore, it was understood that service organizations must manage their customers differentially according to their level of experience.