Michelle, great post. One thing to take into account for “Interest Groups 2.0” is that as technology evolves, the social experience that you can provide to people online can mimic more the interest at hand. For example, if you are a cyclist, you use Strava to track your rides/socialize with others, and Strava is only possible now since we have prevalent mobile devices/GPS tracking. Previously, there were “cyclist forums” in the internet. But only some minimal fraction of cyclists would enjoy reading/writing about cycling. What most cyclists enjoy doing instead is actually cycling. So “Interest Groups 2.0” social platforms have an opportunity to use new technology to provide people with rich social experiences more tightly linked to the interest at hand.