The Community Market is designed to expand the Steam Economy beyond trading. Players are now enabled to buy and sell in-game items with other players for Steam Wallet funds.
"With over a half million trades made every week, the trading system has been very successful," said Tony Paloma of Valve. "Extending game economies beyond trades and giving players a way to turn gameplay into funds for new items and games is a key component for moving that success forward."
The Steam Community Market, now in beta with Valve's Team Fortress 2, will be available to other titles on Steam in the New Year. Games that participate enable users to show off their items on the Steam Community and sell or trade their items to others.
Items purchased are subject to transaction fees, please see FAQ for more details