Only 200 activity points, there is no level or member limit or anything like that. A lot of smaller groups just don't bother because they have no chance of winning rather then they can't.

If you go into rankings then Group, there is 3 tabs, GNW, Power, Activity. Maybe they really are to small to get 200 but i find that there is always less playing then total possible, so i guess some just don't bother.