Former Valve writer Chet Faliszek has a confession to make: Valve intentionally leaked its own Left 4 Dead 2 trailer. The Half-Life and Portal veteran spilled the beans on the studio's past unconventional marketing tactics in a new video uploaded to his YouTube channel (via Ars Technica). Based on his recounting of the Left 4 Dead 2 incident, Valve "leaked our trailer ahead of time because" the Entertainment Software Rating Board (ESRB) "wouldn't let us release the trailer." So, why are we just hearing about this now? The leaked footage in question appears to be the Zombie Survival Guide cinematic trailer, which maybe not-so-mysteriously appeared online in October 2009, one month before the launch of Left 4 Dead 2.
Источник
IGN