Following Valve's announcement that Team Fortress 2 is now 'Free to Play' for life, the studio has said it remains cautious about extending the business model to other titles.
Valve's Robin Walker told Develop that other titles in the studio's back catalogue may not fit the micro-transaction model quite so well as the cartoon FPS.
"The data we got back from the Mann-conomy Update leads us to believe that TF2 would be more successful as a completely free product," he said. "With just the data from a single product, it seems dangerous to assume that it would be true for all our products.
"Either way, we'll know a heck of a lot more in a couple of months, and that's the kind of thing that gets us excited around the office."
Valve has been rolling out the biggest Team Fortress 2 update ever over the past few days. We've been covering it for you. Go and have a look.