From Fred

Fred Stutzman refuted my ramblings about community. Well, not DIRECTLY...

However, people can't and don't want to be active on too many social network sites. We simply don't have the time to spend checking messages and keeping up with all the action in all those different walled gardens. So that's why we all join Myspace and Facebook, and not your social network.

So the "build it and they will come" proposition is false.