Purpose ‐ Social software emerges as an important and effective tool for customer knowledge management (CKM). However, the supporting role of social software in CKM is not well understood. This paper aims to bridge the gap by studying the implementation of social software to effectively manage customer knowledge assets. Design/methodology/approach ‐ The paper analytically models and investigates the optimal level of social software for a firm who maximizes its transactional benefits through managing a consumer knowledge system. The system consists of a customer knowledge base and social software that dynamically affects the customer knowledge base through customers' interactions. Findings ‐ The paper shows that the optimal level of social software can be obtained under certain conditions and how the level changes with the initial index of customer knowledge base, transactional benefits, and the positive and negative effects of the social software. In addition, it provides guidelines to implement social software based on the analytical results. Originality/value ‐ This research provides valuable insights and guidance for the practicing manager and lays the foundation for future research on social software and CKM.