This is curious. Valve's games are now available to buy on rival digital distribution platform, Impulse. Oh 2012, you so crazy. Actually, this makes sense. Impulse was acquired last year by mega game retailer, GameStop. When all you care about is selling games to the most people, as a corporate entity like GameStop would, then you need to get the biggest games on your service. Valve's games are on their shelves (remember those? Planky things for storing stuff), so there's no reason why they shouldn't be downloadable, either.
Of course, the Impulse versions of Valve's games, which includes both Left 4 Deads, Portal 2, The Half-Life Complete Collection and The Orange Box, all require Steam activation, anyway. So customers will be buying into Steam as well as the games.
That doesn't faze the excitable chaps at Impulse, who announced the move in an exclamation-laden blog post.
Some of the greatest, most creative games of the past decade (and the one before that) are now available! Legendary developer/publisher Valve is now available! Whether you enjoy hitting things with crowbars, the power of gravity, making holes in walls or making large holes in the undead, Valve’s games will suck you in and won’t let you go! There’s more quality gameplay here than you can shake a crowbar at!
Remember last year when Impulse's original curator Stardock launched their games on Steam? The universe sought balance.