More than $2 million has been generated through Team Fortress 2 microtransactions, Valve has said.
The free-to-play shooter allows players to create, buy and sell virtual items to wear during games of deathmatch.
The Washington-based Valve said the microtransactions economy generated the $2 million in less than a year since its launch.
The economy will again be updated soon with a new interface that is hoped will make it easier for customers to create virtual goods.
Both the virtual currency and free-to-play updates have transformed Team Fortress 2 over the past twelve months.
The game was released as a more traditional first-person-shooter in 2007, but quickly it epitomised Valve's 'games as a service' strategy - a philosophy of consistently evolving and updating games through user feedback.