Quoting Fistalis, reply 2Developers apply to steam.. and if they are lucky the get allowed on to steam.(and they usually are not told why they are rejected when they are) Steam isn't the great open source savior of indie games that people try to paint it as. Its more like the pissy bouncer at the club.
So ya.. its doubtful stardock has any sway over what steam decides to put on its adverts.
I'm not sure I follow. Obviously Stardock would have to pay. Or maybe they forfeit an extra large percentage of revenue? But if Stardock wanted to advertise via Steam, Valve surely wouldn't say no. They'd say "how much?".
Seeing as its hard for many devs to even get their games ON STEAM in the first place I assume steam keeps tight controls on what they choose to feature/advertise. The fact that the system to even get your game onto steam is rather arbitrary leads me to believe that the advertising system would work similar. That is to Welcome big names and maybe or maybe not support smaller publishers/devs.
Is it possible its just a matter of money.. sure. But Given steams selection process with games accepted onto steam its probably based more on personal whim.