
Towards the end of the speech, Newell showed a slide which revealed that Valve sold one-third more copies of Left 4 Dead on Steam last weekend than it did when it first went on sale (and roughly 3,000% more copies than it did two weeks ago), thanks to a combination of a 50% sale price offered, new content announced, and free trial passes handed out to certain players. According to Newell, the excitement generated by all of these methods magnified the number of sales over what he would expect to see from each of them individually.
Tonight at the D.I.C.E. Summit in Las Vegas, Valve co-founder Gabe Newell gave a keynote speech titled "Entertainment as a Service." For much of the hour, he spoke about the principles that have guided Valve in recent years -- the idea that development on a game like Team Fortress 2 is as-if-not-more important after it goes on sale than before, due the ability to keep customers interested by providing new content, fixing bugs, and adding new ways for them to interact with the game.