Utilizing the Social Graph as a Relevancy Source for Data Ranking

The problem I see with most attempts at using the social graph for problems like this is that most social graphs have no notion of expertise. Tom may be a good friend of mine who shares my interest in cooking and scuba diving, but he works in a Windows shop coding in Java for enterprise apps while I am a Mac user who does large-scale consumer service development using Python and Erlang. He also likes the Patriots, which calls into question any opinion he may have about sports :) Capturing the different facets of "relevancy" is hard, and it does not sound like this comes close to being able to distinguish signal from noise when coming from a source that otherwise might appear to be trustworthy.

Glancing at the front page, it seems that the social graph is made up of technophiles and business junkies.<p>But then, we knew that, I guess. It's just funny, this is basically SF/NYC tech/business talk, while a trace over the RL social graph would probably bring up something more like Us Weekly or ESPN. Even at a sample size of 1, I talk more tech/biz online and more ESPN offline.