If you like stock market games and products, you’ll probably get a kick out of Smarkets. This website allows you to create an account with $10,000 which can be used for trading products whose prices change based on Amazon.com sales rank. I created a trading account and I’ve begun adding some products.
As far as market games go, Smarkets sounds more captivating than Blogshares. It will be interesting to see, when membership reaches a critical mass, if the market is any good at predicting sales for these products.