"But that doesn't change the fact that any social network launching in 2012 that isn't mobile-based, is most likely doomed to fail if it wants to reach a mainst

"But that doesn't change the fact that any social network launching in 2012 that isn't mobile-based, is most likely doomed to fail if it wants to reach a mainstream audience." I disagree. If I were to make a social network now, I would still go web first.