GigaOM delves into the success of Valve Software’s online game service Steam. Through some speculation and an interview with Valve’s Marketing Director Doug Lombardi, the article seeks to trace the growth of the service and try to expose the statistics that drive its success.

Some of the interesting numbers in the article include the 8 million users on the service, 5 million that connected within the last 30 days. Of the four million units of Half-Life 2 sold, one million of those are estimated to have been downloaded via the Steam service. Gamers that chose online distribution paid full price for their game, meaning that approximately 50 dollars per download would go directly to Valve.

Steam has also help act as a hit-maker; independent games that suffer on store shelves can blossom on the service. Apparently, this can work the other way as well, with online offers driving retail sales. Utilizing Steam to offer an ever growing catalog of game experiences would seem to allow Valve Software to leverage the “long tail” business model.