Valve president Gabe Newell said this about the growth:
Steam is on track to record the biggest year in its six year history. The year has marked major development advances to the platform with the introduction of support for Mac titles, the Steam Wallet and in-game item buying support, and more. We believe the growth in accounts, sales, and player numbers is completely tied to this work and we plan to continue to develop the platform to offer more marketing, sales, and design tools for developers and publishers of games and digital entertainment.
In addition, the company's Steamworks publishing services suite, which includes their anti-piracy solution (they specifically avoid terming it rights management), has now been used by over 200 games. Steamworks also enables access to their cloud-based game save system called Steam Cloud. Since starting in 2008, more than 100 million files have been saved using the system.