One Community Does Not Rule Them All
Online communities attract many users and have replaced search engines as the primary entry point to the Web. But, while some community platforms show a tremendous growth in terms of registered users, generated content and visitors, others at a certain point in time do not manage to acquire new users or even lose active or inactive members. A typi cal pattern that can be observed is a major player absorbing the members of another community. This pattern of a hostile takeover of a community is frequent but not universal. The examples of Flickr, LinkedIn and Twitter all grow despite Facebook's dominance over other platforms and seem to be able to coexist peacefully. In this paper, we present a meta model based on community facets of user requirements and technical platform features, to capture dierences and simi larities of communities. We analyse a set of publicly known online communities and observe that competitive platforms in fact turn out to have very similar proles under the pre sented facet framework, while communities with notably dif ferent proles are more resistant to a hostile takeover from each other.