Valve lifetime retail sales figures

HalfLife2.net have kindly collated some lifetime retail sales figures of Valve’s Half Life universe.  Still no sign of Steam digital content sales figures though.  Gamasutra has more info.

Half-Life: 9.3 Million

Half-Life Opposing Force: 1.1 Million

Half-Life Blue Shift: 800,000

Half-Life 2: 6.5 Million

Half-Life 2 Episode 1: 1.4 Million

Counter-Strike: 4.2 Million

Counter-Strike Condition Zero: 2.9 Million

Counter-Strike Source: 2.1 Million

Counter-Strike Xbox Port: 1.5 Million

The Orange Box: 3.0 Million