Nowadays, e-commerce platforms have increasingly relied on contents generated by key opinion leaders to engage customers and drive product sales. To stay on top of the growth, e-commerce content platforms have introduced rewards and punishments policies to ensure content quality. However, effectiveness has remained less clear. Besides, there is a dearth of research that focuses on such performance-based output control in the extant platform governance and user-generated content (UGC) literature. In this study, based on the reinforcement theory and UGC literature, we investigate the effects of monetary rewards and punishments on the quantity and quality of contents generated by KOLs in the e-commerce content platform context. Using data collected from JD WeChat Shopping Circle, we empirically testified our hypotheses. Our results indicate that punishments significantly increase the quantity and quality of content generated by KOLs. Monetary rewards only have significantly positive effects on the quality of KOLs' generated content. Nevertheless, the magnitude of the effects of monetary rewards is larger compared with that of punishments. Theoretical and practical implications are discussed.