In general, I won't agree to any of the Facebook apps (so, no hugs, no mafia, no egg collecting, etc) because I am put off by the whole "this lets us have access to your friends list, your profile, and what you had for breakfast". One exception I made was installing the app for Sudoku, because it's one of the few games that 1) I like and 2) takes very little time. Along with the Sudoku app was this process where you earn AceBucks for playing, which you can then use for something or other.
Today, in a fine fit of Work Avoidance, I tried to find out what that "something or other" was. I didn't really care, I was going to play the game anyway, but it was still a bit odd to find that what they offered was to use your collected AceBucks to buy tickets which were then used to buy chances at winning some mentioned prize - Boze headphones or a $15 Itunes gift card or a jpeg of a kitten. Huh.
Then the real zinger came out - you need to pay actual cash, $2 for 100 tickets seemed common - to convert your AceBucks to tickets. Now it just feels slimy. But I'm still going to play Sudoku.