Companies sponsoring classic virtual communities (VCs) have recently started to introduce Social Network Site (SNS) features into their commercially-oriented VCs. This phenomenon has forced academia to merge two different research streams thus creating the brand-new research stream of "hybrid VCs". The objective of this book is twofold: We explore hybrid VCs with respect to mass communication patterns and we assess the impact of user-to-user feedback on a user's participation. We hypothesize that a user's participation is impacted by the amount and the quality of information he provides to the hybrid VC. Qualitative, behavioral data stemming from over 40,000 members and generated over the course of four years in a first-generation hybrid VC is analyzed using qualitative, quantitative as well as longitudinal methods. We find that some mass communication patterns can be explained with classic VC and SNS literature while other unexpected patterns cannot be explained with traditionaltheories and call for new hybrid theory building.