If you go on that site you can do a slot machine sort of thing that lets you get discount codes for a few steam games like Trine 2 or Legend of Grimrock. Click "info" for the games and the discounts you can get. Once you run out of ten spins you can just wait a few minutes and then you'll get ten more, so this is cool if there's a game there you want.
The codes all expire on November 20, though. So be quick about it if you want one of the games.