Now that Fulltilt is no longer available (legal) poker players have to seek for new places to enjoy the sweet poker excitement. It appears now that PokerStars have gained more than 66% of the former FullTilt players.
Once the FullTilt website went down PokerStars experienced massive players flow who failed to login to their usual accounts and joined the PokerStars rooms. We should not forget the rest of the 34% gamblers who did not become the PokerStars fans. They have most probably spread through the other online poker rooms.