My vote for the best article on computer games in a long time is ‘Alone together?’ exploring the social dynamics of massively multiplayer online games. Ducheneaut and colleagues at PARC have found a way to gather data from World of Warcraft (WOW) and analyze it for social data. The paper gives a nuanced view of the social aspects of WOW summarized by the phrase “alone together.” Unlike some other MMOGs the game doesn’t encourage socialization. In fact playing solo is more effective for leveling up (until you get to the very top levels.) The social aspect of WOW has more to do with being seen as having achieved. You may not be actively playing with others, but players like playing alone in a game where there is an audience for their achievements and the potential for social interaction.
Interestingly, what seems effective in the design of WOW is the steady leveling. There is always another level achievable with a bit more work.