I also started off in a lot of teams. I joined all the local ones, and soon starting leaving them when I realized they were very inactive. No point in being in a team if there's no one to talk to!
I haven't played around with promotions teams, so I can't speak on that. But the very active teams I am in host their own craft shows, make team coupon books, etc. So there is opportunity to further your reach that way, and feel like you're involved.