Valve writer Chet Faliszek has revealed that Left 4 Dead 1 & 2 have combined lifetime sales of over 12 million.
Falisek revealed the numbers in an interview with VG247, during which he elaborated on how the Valve publicity machine works: "We just let the game speak for itself because the internet has made this thing where, you can't pull the wool over people's eyes any more."
"They're going to know you're hyping. But when a game does really well at pre-release, they're going to know that you're not just talking a bunch of PR crap," he said, before adding: "I mean, the Left 4 Dead series has now sold over 12 million copies. That's amazingly cool, and that wasn't because I was out there like, ‘Oh my god! This game is amazing! Buy it!'"