We've approached the development of Steam the same way we treat our online games; we release something we've tested, we internalize the feedback, and then we release new features and functionality based upon the feedback received.

In Steam's case, we have millions of customers who are gamers and dozens of customers who are developers and publishers. In the past year, we've added over 100 new titles from third parties, grown to over 13 million active accounts, and introduced new features such as Guest Passes and Free Weekends.

This growth has taught us a lot and inspired many additional features and services that we'll be releasing later this year.