Game sales on Steam rose by more than 100 per cent year-on-year during 2011, Valve has announced.
That's the seventh straight year that the PC and Mac portal has seen sales double.
There are now over 1800 games available to more than 40 million account holders. During the Holiday Sale, the number of simultaneous users topped five million.
780 Petabytes of data was served to gamers around the world, twice the amount in 2010, with Steam doubling its service capacity to meet demand and improve download speeds.
Over 14.5 million copies of Steamworks-enabled games were registered during the year - a 67 per cent increase on 2010.
"Steam and Steamworks continues to evolve to keep up with customer and developer demands for new services and content," commented Valve boss Gabe Newell.
"Support for in-game item trading prompted the exchange of over 19 million items. Support for free-to-play (FTP) games, launched in June, has spurred the launch of 18 FTP titles on Steam, with more coming in 2012. Looking forward, we are preparing for the launch of the Big Picture UI mode, which will allow gamers to experience Steam on large displays and in more rooms of the house."