This is an idea I've been working on for the last month or so. I wanted to make a fun and addictive site with a low barrier to participation. After iterating through a few prototypes with friends, I opened the site to the public last week.
Some data so far: The average visitor generates over 50 page views, and stays for longer than 5 minutes. There's significant click-through to Amazon, which is how the site generates revenue. People seem to enjoy the site, but only a few seem to be sharing it with their friends.
I have a Facebook Platform app in the works, which I hope will help to increase the site's virality. In the mean time, I'd be grateful for any feedback you could provide.