>only get recommended that content which has empirically shown is wanted by people that think like them
Seems like an OK idea, but I think the site might suffer if this is taken too far and the groups just become echo chambers, walled off from each other entirely. I just think a site could be more popular if it focused on finding common links in disparate groups instead of isolating them based on common differences. Think of it like radio: in my music directory, my biggest artists are The Crystal Method (41 songs), NIN (112 songs), and Sarah McLachlan (85 songs). No single radio station, AM, FM, or XM, that I am aware of covers a range like that. Wouldn't it be cool to find a place that let you keep close to your core group, but at the same time gave you tips on what other groups thought was cool, just in case you agreed?