Virtual communities have been the focus of research for some time. However, while many studies provide recommendations on how to build, extend and manage virtual communities, few verify the success factors they consider essential for virtual communities. Conclusions made regarding basic preferences and distinct priorities of different stakeholders in virtual communities have not been empirically substantiated. This study uses an online survey of members and operators of virtual communities to evaluate success factors discussed in the literature. Incongruences between members and operators are identified and analysed. This research gains first empirically validated insights into success factors for establishing and managing virtual communities. The study results are summarised in ten hypotheses.