Our LQS just started such a program. Just for signing up, I got a card in the mail for $10 off my next purchase. (Already used that on my class I'm taking.) You get a card, sort of looks like a credit card, that you give every time you purchase something. After it adds up to a certain amount, you get a percentage off, I think... Haven't had the program long enough to really know how it's going to work, and I've already managed to misplace my card, so that's not good, either!