I've been somewhat addicted to Candy Crush for the last few months (at level 305 now - long commutes give me way too much free time) and I haven't spent a dime either. What was surprising to hear was that some co-workers have paid at every "world" change - and they didn't know there was a way to get through to the next world without paying. It seems, when it is hooked up to your Facebook account, you don't have the option to play the three bonus levels over the course of 24 hours each - only nagging FB friends and paying. The trick is to just sign-out of FB in-game, play the three levels and then connect it back up if you wanted to.