Valve's Steam service has undeniably emerged as the most well-known digital distribution platform for PC games, but just how much of the digital pie do they consume? Gamasutra reports that according to internal estimates from Stardock, publisher of Sins of a Solar Empire and owner of the Impulse distribution service, Steam takes 70 percent of the market share.
"Our estimation is that Steam -- as the current market leader -- enjoys approximately 70 percent of the overall digital distribution market with Impulse at 10 percent and all others combined at 20 percent in terms of actual dollars generated per month," wrote Stardock chief Brad Wardell in their 2009 customer report. Wardell goes on to estimate that digital distribution will have contributed 25 percent of revenue "for a typical PC game publisher on a new title" in 2009.
One of the problems in making Impulse more competitive with Steam, Wardell explained, is that developers who use Steamworks in place of DRM are essentially cut off from Stardock. "Examples of this include THQ's Dawn of War II, Sega's Empire: Total War, and more recently Activision's Call of Duty: Modern Warfare 2," Wardell wrote, all of which "limits our content."

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