How do online communities organise themselves?

I don't really know quite what I'm doing yet, so I'll just address this topic first.

So, how do online communities organise themselves? I guess Terry Flew's New Media: An Introduction book is the first to come to mind for this question. In his Virtual Cultures chapter, he argues that online and offline communities aren't separate worlds anymore. The part of our lives that previous were dissociated from the internet have now incorporated our online activities into everyday living and culture. Though our on and offline lives may have merged, according to Flew, each are organised differently in an hierarchical sense. While the hierarchy of an offline community is governed by a physical position, power and authority in online communities are earned through frequency and depth of involvement in that community.

Ok, this is nowhere near long enough and I've had enough.