I for one have had pretty bad luck with rebates....
1st one was half off a stick of 8mb fast page RAM(PNY or Kingston).... this was worth $50 easily at the time... Best Buy didn't have the rebate form in stock and gave us a "rain check" or something a rather... but they never got the rebate form and I never saw the money...
2nd time was on a box of Memorex floppies(at best buy)... they were supposed to be "free after rebate" but I never saw that money either... $20-$25
3rd time was again at best buy.... something like $20 off a Zip drive... I sent in the rebate and UPC... but the rebate never showed up... I didn't bother to call IOmega
3rd time was at microcenter when I bought an ATi TV wonder... that rebate arrived within just a few weeks... something like $10
4th time was on a pack of FUJI film CD-R's(bets buy)... the rebate took 2-3 months instead of 2-3 weeks, but I eventually got it... another $10
So I have been jipped repeatedly by best buy.. the only reason I got the Fuji CD-R's is because I had a gift card I was meaning to empty and the CD-R's were a good deal without the rebate (~$0.25 each)
The ATi, Fuji, and Zip drive rebates were all manufacturer's rebates if I remember correctly(ATi and Fuji for sure)
Personally, I think rebates are mostly a scam so that companies can get your money and then claim that you either (1) never sent in a rebate (2) you failed to fully comply with the rebate's terms or (3) that the rebate must have gotten lost... and then there are the people that probably never send in the rebate at all....
I wish that manufacturers would just use coupons and that you could take the coupon to the store and get instant gratification... leaving it up to the retailer to send in the coupon and quibble with the manufacturer if there was a problem.