These are a method of offering a discount without offering a discount. If I'm behind the 8 ball, I'll buy something with a mail in rebate. Otherwise, I will not purchase the item. I hate gimmicks and that's what mail-in rebates are.
What do you think about rebates?
Never, it's not worth the hassle
Only if the rebate is big enough
A pain in the butt, but I still fill them out
Love them, I fill out every rebate form
I think most rebates are scams; companies never pay up
Other (tell us what you think)

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic