It's certainly a good idea, but they're not the first to come up with it. Plasticjungle.com seems to have been around since 2006 and looks very similar. A quick Google search for "sell gift cards" reveals several other similar sites as well.
YC has always had a penchant for poppy, Hanson-esque startups, but this one is flat-out embarrassing. They turned down CouchDB but picked up a gift card exchange? When did Dr. Paul Graham, author of On Lisp, turn into pg?
First, for this gift card thing, where is distribution and SOM? Those are cornerstones and as my Mama always said, "Bridges without cornerstones are fally." I'm not saying the guys behind it have done something wrong. Their mandate is "pay the bills and buy a lottery ticket at the same time." I hope it works out for them.
But you didn't ask about that. You asked, "What makes CouchDB a better investment?" Well, it's technology. And even if it doesn't get the business case, it can lend a role in someone else's business case. You've advanced the world a little bit. You've fought the good fight.
I mentioned Hanson. What if a record company, founded by good musicians, had Hanson and Glenn Gould sitting on their couch and said, "Sure Gould is amazing, but will teenagers buy it? Let's fund those Hanson boys." You would question their intentions and if they really ever understood music. You would be embarrassed for them. You can't always fund the Goulds of the world, but there's a level of superficiality that you can always rise above.
