When I was back in my academic thesis writing days my two Academic idols in Social Media Marketing were Susan Fournier and Danah Boyd. Danah has the biggest online bookshelf of online social networking academic papers. If you can understand academic jargon, that link is like pure gold, you will even see my ol' thesis get a mention. ;)
Anyways, Susan Fournier wrote my favourite paper, she cracked the idea of Brand Relationships. In a nut shell, we have relationships with products and brands similar to how we perceive our relationship with people.
Fournier has come back again and written a cracking article on Brand Communities in Harvard Business Review. Get ready to have your mind blown. Here is a taste, I am going to get a few more blog post out of her article.
Spot on, I think that Facebook Fanpages act more as badges rather than communities. I do not see that much conversing going on, it is more about just associating with those brands.