Unravel the Drivers of Online Sharing Communities : An Empirical Investigation

Recently user-oriented online sharing communities have seen explosive growth. Two characteristics of these communities set them apart from traditional online message-based communities such as online forums. First, users have no social ties before joining the community. Second, there is little or no "verbal" communication between users. This research investigates the structure and dynamics of online sharing communities using data collected from an IRC music channel from 2001 to 2006, covering all five years of the post-Napster age. We have collected more than three hundred million individual activities, capturing 0.05% of the global music sharing volume. We find that sharers are an essential part of the community and their activities have a dominant impact on the growth of the community. By contrast, free riders have two opposite impacts on sharer retention. More free riders in number make it more likely for a sharer to keep sharing, while more free rider activities discourage sharers from contributing. That is, the existence of free riders, despite the congestion caused by their download activities, does to some degree stabilize the community. Most previous literature examines the online community only from the aggregate level. Our study, nevertheless, distinguish the influence and behavior of different members in the community. Instead of paying only attention to the total number of users, our results suggest that understanding the impact of their core members is critical in investigating the dynamics and the sustainability of online sharing communities