One part time coder, me.
One full time marketing, community manager, admin, spell checker and bug fixer.
And would say 3 "game admin's" not including those in GalacticLords.
I would like to say, and repeat, this can only be done when you have a fully functional and useful admin panel on each site. We just bought GalacticLords and the admin panel was far under par then what we use internally. Not to say it was bad, just that we have very high standards and tools when it comes to admin'ing games. I would say more development has gone into the admin panel (it's now pretty much plug and play into new games) then the actual game itself.