[this_is_gav]

Because they'll still not lose much, even through offering this. Very few will take advantage, and next to none in pre-built systems (which will account for quite a percentage I'd imagine - most enthusiasts were waiting for the ATI cards before committing), if they can at all.

It's like the cash-back offers on low-end DSLR cameras that Canon and Nikon always seem to have. They rely on some/most not taking advantage of it to make up for those who do.