Analysis- Valve's Lifetime Retail Sales For Half-Life, Counter-Strike Franchises on Gamasutra may come up a little short in analyzing Valve's sales data, in part because the significant amount of digital distribution they've done is not part of the data on sales that have been released. It doesn't take much analysis to say they've sold a lot of copies, though, as word is that they've sold 9.3 million copies of Half-Life, 6.5 million copies of Half-Life 2, and all told Valve has sold well over 36 million copies of their games at retail over the last decade.