@kaiapo On the other hand, considering that those were developed by Stardock there should be no reason to assume that they would be on another site. Similarly, you won't find any of the half-life games ending up outside of steam. When a DRM system offered up for free locks down a third party game to a single DD system, that is anticompetitive behavior.
So, it is ok for "some" to be cutthroat but not everyone? Well...I suppose it is the very definition of cutthroat business to be unfair.
Anyway as Firbolg already pointed out in both cases there is "anti-competitive" (or just competitive depending on the point of view) behavior.
On a different note this is something I'm curious about:
Gamersgate, the other big DD site was owned by Paradox. I'm not sure what was involved in them releasing Gamersgate to be an entity on it's own and they still have a small part in it, but their games are now sold everywhere. Impulse, Steam and Gamersgate alike.
It is possible to assume that they felt that the interests of Paradox as a publisher were conflicting with Gamersgate's interests and decided it would be best to have Gamersgate be a free company.
One could make the case about Stardock and Impulse too. I'm sure sometimes they debate if they could sell more game if their games were everywhere and not only on Impulse. My guess is they think it is still more profitable to stay with Impulse's monopoly.
In the end it is about profits. I really don't care much for Steam. I much rather have my games bought through Gamersgate but I fail to see how Steam needs to be labeled the big bad wolf out there when all I see is everyone doing the same thing.
In other words. If you bought GalCiv or Elemental, a Impulse monopolized game, what is the difference if you buy Civ5? Other then of course you not liking Steam as an aplication, which is a totally different thing.