And here I thought that Tribe was in the ZombiePool. Paid features has certainly worked for LiveJournal, dunno what sort of add-ons tribe can come up with.
Tribe Premium: "The overwhelming consensus is that our users love tribe.net so much that they are willing to pay for a premium subscription for all the functions that we now give to you. We’re excited (happy? grateful? nervous?) to say that we’re going to launch the premium subscription service next week. Between November 30th and December 15th we’re going to offer premium subscriptions at five bucks for thirty days. "