Revenue/User in Social Networks

I saw this comment at:

http://tristateventuresblog.com/2007/10/25/microsoft-facebook-aoltime-warner/

No social network has been able to surpass the $3/user/year mark. Facebook has a shot at it though, they need to do a lot of work and I think could double it to $6 per user per year. Myspace i believe is around $5/user/year now. It takes years and luck to go beyond $3. I don't know why but that's been the magic number. And that's in a popular network, smaller networks generate less revenue. Myspace was at $3/user/year in revenue when they were acquired. Facebook's value is users actually like being on facebook. Facebook needs a social search engine and email platform though.

Comments?