In fact, only 1.1% of players return to the game after a 3rd consecutive day in the game. If you're the type of person that logs into a social game every single day you're one in one-thousand. The study also has numbers on which days players are most likely to spend money on, the amount of time played by those who are in the .1% and those in the 90%, and many more surprising statistics.
If you've ever wanted an in-depth look at social gaming this is a study worth looking at. Read the full study here.