The whole converting currency to use their credit system seems a bit too eerily similar to gambling for my tastes. Not really sure how this site would be any better of an option than eBay, Amazon, etc.
It isn't a "better" option. It's a different option. It is a lot like gambling. You can get a lot for cheap or you can lose it all. I edited my post cause I gave it a shot...and spent 91% less on a TV than if I had purchased it in a store.
Edit: I also spent a bit of money to try to win a camera and didn't. Nothing ridiculous, but enough where I decided to stop.