Generally, I agree. There's a time and a place for both online and offline venues.

Ideally, you'd want a very large number of participants such that, during sessions, most of your peers are new and the situation is somewhat anonymous/random. If your sessions are with the same old people, these people will become well known -- perhaps friends, and the social simulation won't be very meaningful. Who knows.. maybe there's a way to piggyback on the Chatroulette concept?!