Electronic Arts' Origin service is running a three-for-the-price-of-two sale, on selected titles, this weekend. Three of the eligible games are published by Valve. EA and Valve haven't been very friendly of late, so perhaps this is a make-up gesture by Valve?
[Correction] As everyone points out, EA was the distributor of these games' retail versions. That's probably got a lot to do with it. And the fact these are physical copies, not digital downloads. I'm leaving the rest of this up so you can laugh, again, at what an idiot I am, but it's all non-operative.
The Valve games involved are Counter-Strike: Source, Left 4 Dead: Game of the Year Edition, and Left 4 Dead 2. Pick two and get a third free. No Valve game is in the group of "free" candidates.
In early August, Electronic Arts confirmed that Battlefield 3 would not be released over Steam, saying "the service limits our ability to deliver patches and downloadable content directly to players." EA gave the same reason when Crysis 2 disappeared from Steam about a month after Origin launched.
Recently, Valve boss Gabe Newell told Kotaku that they "really want EA's titles on Steam. ... We want to do a good job showing EA that we have value on Steam. We'll try to work hard with them."
Maybe this is part of a thawing in that relationship. Who knows?
[h/t Mechy Tiki]