I don't think that's entirely true. For me, the great thing about the internet is that some of these "tribes" are actually pretty diverse in their viewpoints.

I don't think that's entirely true. For me, the great thing about the internet is that some of these "tribes" are actually pretty diverse in their viewpoints. They form loose communities based on currencies of quality (thoughtfulness, analysis, originality) instead of specific views. Specifically, I'm thinking of the bloggers/twitter users who write about political/econ topics. A lot of the good ones are non-commercial and ad-free and aren't looking for public acclaim.