Brad Wardell, boss of Stardock and digital distribution platform Impulse, reckons Valve's Steam is miles ahead of any competition in the PC gaming download market.
"Our estimation is that Steam - as the current market leader - enjoys approximately 70 per cent of the overall digital distribution market with Impulse at 10 per cent and all others combined at 20 per cent in terms of actual dollars generated per month," wrote Wardell in a company report this week (spotted by Gamasutra).
Wardell also feels Valve is beginning to monopolise on its position by integrating Steamworks tools into games at an early development stage and essentially locking them out from other digital distribution platforms.
"Another trend we have seen in the past year has been Valves successful work with getting Steamworks licensed as a DRM solution by major publishers. Once a game requires Steamworks, it is effectively cut off from us, which limits our content," he said.
"The problem is that it is not practical for us to install a game that in turn requires the installation of a competitors store and platform in order to play it."
Wardell said Valve and other competitors had "a significant headstart" signing regional distribution content, but admits that getting content quickly is "an ongoing challenge".