^yeah, but they never have an unlimited quantity, they specify how many they are going to make deals of before they start this.
And it's not while 360 console supplies last, it's how long the gift card quantity lasts. Sure a store should have thousands of gift cards lying around, but at any point they can just say, "we don't have any more 360 gift cards available", yet they would still be able to sell those non-giftcard-360s to people who have already concluded to buy one.
It's while 360 supplies last. Their giftcards are pretty much unlimited. It takes any card, not some special one for the 360 deal. They can take any Walmart giftcard and apply the $100 deal to, even to existing gift cards people already own. I was asked when I purchased my 360 if I wanted the gift card balance added to an existing one.
And as far as the "while supplies last" I was told by the Walmart manager it was while they kept getting 360 shipments.