It takes a little longer nowadays as it's so huge. When I joined 2 years ago there weren't as many of us. After time, however, you should find that you 'get to know' those who post to similar groups, or who have similar tastes/styles of photography.
All I can suggest is that you keep commenting on people's work and keep posting to group discussions. Follow your contacts' photostreams regularly. There are plenty of friendly folk out there.
Would certainly recommend Utata but you have to visit every day to keep up with the many discussions going on.
It always takes time with new groups/sites (I'm finding that here) but give it time.