ABSTRACT
Virtual communities are originally intended for a variety of needs, varying from communities of interest (intellectual Web sites), communities of relationship (Twitter, MySpace, etc.), gaming communities (e.g., in World of Warcraft, Second Life), or communities of transaction to peer-to-peer communities (eBay, Amazon, etc.). Web 2.0 mechanisms are also boosting the development of virtual communities (used for cell phones or PDAs) and the role of user-generated content within virtual communities.
