I run a facebook breakup support group for men. About half of the people that request to join the group discover the group themselves on facebook. For me as a

I run a facebook breakup support group for men. About half of the people that request to join the group discover the group themselves on facebook. For me as a website owner (rapidbreakuprecovery.com) the group has been a convenient way to offer a forum-like functionality without any of the overhead involved with running forum software. I suspect facebook users have come to expect that these types of groups exist and they're typing things such as "breakup" in the group search field. There other breakup support groups that are routinely recommended in the sidebar as well as a support group specifically for divorced dads. So it seems that facebook's scale is allowing smaller niche communities to exist where they would not have existed before. From a usability perspective it's not great. It's easy to set up and it's easy to get members, but I would happily switch to something more discrete, and that's a better fit for support group dynamics (interesting idea by sodosopa).