Waay before FB, a bunch of us used East York data to do an in-depth (small sample) study of how/when networks change composition. Marriage, childbirth were biggies Barry Wellman, Renita Wong, David Tindall and Nancy Nazer, "A Decade of Network Change: Turnover, Mobility and Stability". Social Networks 19 (January, 1997): 27-50 Barry Wellman A vision is just a vision if it's only in your head Step by step, link by link, putting it together Streisand/Sondheim _______________________________________________________________________ NetLab Network FRSC INSNA Founder http://www.chass.utoronto.ca/~wellman twitter: @barrywellman NETWORKED: The New Social Operating System Lee Rainie & Barry Wellman http://amzn.to/zXZg39 _______________________________________________________________________