Further, I don't think everything is "communityfiable". Like I said earlier, interesting conversations don't happen often, so stuff like following a person due to his one email upload or whatever, recommendations etc all seem a bit too much. Following would make sense if it is someone who uploads stuff often, but in this case anyone who does it would be breaching someone else's privacy unless the uploader is part of the conversation and everyone agrees to share it. But, again, as I said earlier, interesting conversations happen only once in a while.
That said, I remember how twitter was derided in the beginning as being a platform for people to share boring stuff that no one cares about, but it turned out to become something else, though not by design but only by chance, and is now quite successful.