Poker sites will offer daily freerolls to build a customer base mainly,so once they ve done that,they will slow down or even stop them.Everleaf sites are notorious for this among others.
Back before the uigea,you couldnt find a freeroll anywhere that didnt fill up with 10k players in 10 seconds.All their money went to expensive advertising.So it will prolly go back to that when the online poker debate/uigea is settled,so enjoy all you can now!I really like it better this way in alot of ways.