Most people get lazy and forget/don't have the time to do the rebates. I usually do mine, but I just missed two rebates ($40). My parents came really close to missing a few of their rebates on some hardware too.
And the rebates come from different places. There's the store rebate which can either be in-store or mail-in, and there's the manufacturer's rebate, obvioulsy that's mail-in.
On top of that, most people don't do the price match thing. Vendors and manufacturers know this, and they're kind of expecting you to buy something from one place, and just stick with it. I should get my friend to talk here... He's good at getting a lot of things for free without having to do referrals or anything like that. He's gotten a few iPods, RAM, PSP, a few cell phones, just to name a few for absolutely nothing by looking in the right places.
If I were him, I'd sell the iPods and get a better DAP, and some other hardware. But then again, he could probably get those other hardware and better DAP for free too...
He's really just that good. Well... he's been doing it for a long time.