: This research develops, operationalizes, and empirically tests a model for explaining/predicting the satisfaction of customers with Internet-based services in the context of an on-line knowledge community. It empirically demonstrates the need to consider not onlythe expectations of customers but their desires in explaining/predicting their satisfaction. The empirical results show the superiority of the proposed model to those used in previous research. In addition to its theoretical contributions, this research identifies specific desires and expectations that drive the satisfaction of customers of Internet-based services. These findings should be of great interest to both researchers and practitioners. KEY WORDS AND PHRASES: Customer Relationship Management (CRM), customer satisfaction, expectation disconfirmation, Internet-based services. Internet-based services are proliferating rapidly. In addition to Internet companies, traditional organizations are developing capabilities for p...