A new feature for users of Valve's popular Steam service that allows in-game items and gifts to be traded went live Tuesday.
The feature, called Steam Trading, started an open beta about four weeks ago with support for the company's Team Fortress 2.
Today's public release has added support for another popular Valve title, Portal 2, as well as a third-party title, Three Rings and Sega's Spiral Knights.
According to Valve, over 1 million virtual items were traded or gifted during the beta period.
Valve introduced a popular virtual item storefront for Team Fortress 2last year.
The game recently went free-to-play, and is running on a business model supported solely by these virtual item sales.
