One thing I wonder about ratings is, are you measuring a user's individual interests, or whether they think the content is good / bad / shareable? And what do

One thing I wonder about ratings is, are you measuring a user's individual interests, or whether they think the content is good / bad / shareable? And what do the users think they are ranking? Personally, I'd rather be ranking for what interests me, so that I get more of that; but I feel most networks are trying to extract a different signal, and that this produces crappy recommendations and useless rankings.