GOG.com Gifting Club (Steamgifts) is most fun. So many giveaways, only open to the member so the odd is not as crazy like public giveaway. Usually the entries ranged from 10 - 40, depend on the popularity of the game.
Even some generous user offer 3 copies of Skyrim last weeks, but of course the entries were much higher than usual giveaway (80 ++ entries); it was Skyrim afterall.
I only won once, and that was Duke Nukem DLC; only 3 peoples entered the giveaway at that time.