I've never understood why non-Steam games don't just have an "import fee" or a slightly higher price.
For example, I can't buy Mass Effect 3 on Steam. Why can't Steam charge that extra 30% over the price of the game, so that EA does not lose that revenue (not considering the DLC policy problems). EA would not lose money, and Steam would not lose money. I would be paying a small premium for the luxury of using the game on Steam. EA, especially, is being short sighted.
Same thing for Minecraft. Just sell the game on Steam for a slightly higher price. Or, perhaps let Valve charge me a small fee for allowing me to activate a game key on the service because I bought the game through the web site.
Notch, EA, everybody is being very short-sighted here. Steam is much more than a store. It is a storage facility, a social site, a store, a community, and much more. Many people, would be more than happy to give Valve a small fee just to keep *one unified game library* using one piece of software.
Steam, as a service, has value to a lot of people. Many would probably pay a small additional fee, enough to make up the lost 30%, just to have ALL their games in that one library.
To top it all off Notch, EA, Valve, everybody is leaving money on the table here. I mean, how many people on here have bought Battlefield 3 through Origin, but would happy give EA/Valve and extra $5 to activate the game on Steam? Or, at launch, would people have paid $69.99 instead of $59.99 for a "Steam enabled" version of the game? ...EA were using BF3 as their foothold to get Origin started, but now that it is up and running, I don't see why such things couldn't be done in the future.
I've always kind of wondered about this too. I think it would be perfectly reasonable for a dev/publisher to do something like this, especially if they were transparent about it. It might go over better if they said "we'll split the cost, only 15% bump in price."
Edit: The price of the game isn't going up. You're just paying to get it on Steam from a developer/publisher who isn't willing to lose 30% of their revenue to Steam. This already happens, people regularly buy games that are more expensive on Steam than elsewhere because they are on Steam.