In recent years, social networking systems have become quite popular, and have been established for a variety of purposes. However, it is still not well understood if sense of community (SOC) contributes to an individual user's continued usage of these systems. This paper presents a theoretical model combining key constructs from the SOC framework and the information systems usage/success models to evaluate social networking usage. We surveyed users from popular social networking sites to test the validity of the research model. Our results indicate that while user satisfaction is still the most salient determinant for system usage, SOC also plays a significant role in the user's online social interaction process. Besides its direct influence on usage, SOC also indirectly influences usage through user satisfaction. In addition, we show that SOC is a multidimensional construct that should be measured using several components. We also demonstrate that the quality of the information contained in the communities has a significant impact on SOC, but system quality does not seem to influence it. Theoretical and practical implications of the study are discussed.