Why are they doing it? I have no idea. Nice deal, though, if you want a gift card (or want to reserve future savings for your own shopping).
This offer will not combine with the Google Checkout deal, by the way.
So go buy some gift cards, and then the people you love can buy tents. And backpacks. And underwear. And… ummm… other stuff. You never really know what you’ll find at Sierra Trading Post, really, but I’ve been happy with everything I’ve bought there.