Here is a compelling Web game for anyone even remotely interested in stock markets, prediction markets, or just in Amazon.com products. =)

Smarkets is a browser-based stock market game for products sold on Amazon.com. Each product available through Amazon becomes a stock that you can buy, sell, short and cover. When you sign-up for the game—simply by creating a username and password with an email address, no other information or validation is necessary—you are given a virtual $10,000 to invest in anything you wish.

Stock price is determined by Amazon's sales rank. If the sales rank goes up, so does the stock price (based on a pricing formula). Products are grouped with other like products with tags, and then compared with other groups like it. A stock (product) not already in the market can be introduced simply by entering its Amazon Standard Identification Number (ASIN), a 10-character code that can be found on every product page.

The game was created by Steve Odom as an experimental prediction market to learn whether markets that are set up to trade products can predict sales of those products, or groups of products. Very cool. Click.