Any RTS that is not WC3/SC will probably have about the same (if not less) amount of players as Demigod.
The Dawn of War 2 beta had an average of 8,367 unique users playing Dawn of War 2 throughout the beta each day, and an average of 25,335 matches occurred between the 1st and the 14th of July.
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That was the "opt-in" beta for those who already owned the game, not the open beta before release.
I think DG is below average for player numbers, just like SupCom was. The FA community is still alive and kicking though from what I can tell (the boards are pretty active) because SC/FA offers something fairly unique for online RTS. DG's long term survival depends on it providing something different to HoN/LoL, not on it being a better version of the same thing.
In other news Valve hiring the original DotA creator could be awesome, I'm keen to see what they can add to the strategy genre having stuck with FPS for so long.
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