Nancy, I have just completed my MSc in New Media, Information and Society at LSE and am currently working at the BBC is Radio and Music Interactive; I have had a meeting with last.fm guys. Not surprisingly the CTO is very young as are most of his team, they developed the idea whilst at university. We absolutely love what they are doing! So they are computer scientists, not social scientists. This is a very important distinction, what you have described is a classic example of unintended consequences / social shaping of technology. These guys only have their perspective through which to try and understand what it is their users want, but they are not social scientists. If only they and other social networking sites had a trained social scientist on staff! I feel extremely fortunate in that in my undergrad degree I trained as a computer scientist and my postgrad as a social scientist - I feel very well equipped to see both view points, the biggest problem is that scientist are very binary, they really don't like fuzziness We have done an interesting experiment with last.fm, we set up user accounts for our radio stations and pump in the songs played in real time, this has generated some very surprising findings; one of our radio stations is currently a very good predictor of future pop music trends. I find last.fmvery very interesting, but these guys are still working out how they will make money.