It is path dependency. If most of your friends are on FB or MS, then you will choose that one. I haven't seen hard data on socioeconomic differences, and I'd be reluctant to generalize that FB is mid-class and MS working-class. You're seeing local clustering, which may not be consistent across localities or interest groups. Often, it is based on just a local seed (one of the pitfalls of statistical cluster analysis, btw). WHy, for ex, is FB hotter in Canada than the US? I doubt that it originally had much to do with a nicer interface. Two notes on terminology: 1. Consistent with Lauren Squires, I'm running a small conference Nov 1-2 with the title "Social Network/ing". It's mostly academic, with some industry attendance, and mostly local, but with visiting speakers: Keith Hampton, Caroline Haythornthwaite, Nan Lin and Fernanda Viegas. (and Jon Kleinberg on Oct 30 as a stand-alone). Attendance is free, but we don't do anything for you: find your own room and restaurant. (But do let me know if you're coming). 2. As for terms, altho I like danah's "friendstering", I have been using "linked" for many years -- well before the LinkedIn folks started, and I still think it best represents the FB/MS phenomenon. But Naomi Baron might know more about this. Barry Wellman _____________________________________________________________________ Barry Wellman S.D. Clark Professor of Sociology NetLab Director Centre for Urban & Community Studies University of Toronto 455 Spadina Avenue Toronto Canada M5S 2G8 fax:+1-416-978-7162 wellman at chass.utoronto.ca http://www.chass.utoronto.ca/~wellman For fun -- updating songs, movies and history: http://chass.utoronto.ca/oldnew/cybertimes.php Elvis wouldn't be singing Return to Sender now _____________________________________________________________________