I'm saying that the reasoning a lot of people seem to have--that Steam is selling things for cheap because they're superawesome and love gamers and just want to generously give you the chance to play all these games--is fallacious. It's purely business to them, leveraging their already massive market and advertising power to take advantage of impulse shoppers and kick the competition in the gut in one shot.
The more power Steam gets, the more leverage they have over the industry, and the worse it'll be for everyone who isn't them. Lots of competition among similarly-sized outlets, with vendor-neutral solutions for achievements, community, etc., is a far more ideal situation for consumers and producers. See here for more about our philosophy in this regard.
We've heard this before, pretty much from any store that tries to compete with Walmart. The fact is, most people are not going to spend twice as much for a game at Impulse when they can get it at Steam at such a bargain. Morales aside, money talks. Your sale was buried before it even started thanks to Steam. I have no illusions that they are doing anything for the good of gamers. I have certainly voiced, on a number of occasions, things I don't like about Steam. I also know Steam is DRM despite what some of their biggest fans suggest. I am still going to buy their four packs and enjoy gaming like it should be done, with my friends for hours and days and weeks on end with games we weren't willing to shell out 50 bucks for but find entertaining and worth it at 20.
You might want to take the blame the consumer role, and try and pretend like the only people who buy from these amazing sales are just throwing their money at games they won't play or enjoy, but I am not buying it. My first purchase from Steam was during the big Christmas sale, and now I am working on five or six games and the list is growing. I've sense referred Steam to 3 or 4 people who have also purchased from and now use Steam based solely on price. You know how many people I can get interested in Impulse, almost zero. The sales are not exciting at all. Most people haven't ever heard of Stardock (although to be fair Valve isn't as well known as Steam either). The selection is severely limited here. And despite the software and methodolgy of distributing games and the ability to use non-impulse expansions (at least i think this works), few people care enough about the morale high ground to choose Impulse over Steam.
Given the choice between the two, at the same price, Impulse wins with me, but that rarely happens mostly because of these sales. I think Steam is smart giving a great sale to get new and existing customers talking about them all over the internet. Kudos to them for that. This sale as me checking Steam daily now for the duration of their sale. And let's see, oh yes, I have Impulse to start on startup so I could get in on those great promotions that stopped coming weeks ago, and the only reason I know there was a 15% sale going on is a I happened to see it mentioned on CAG. So i guess there is no reason to have Impulse be a startup application anymore because clearly the promotions reminder is now non-existent.