Popular free-to-play shooter safeguarding long-term survival of the US studio, says Robin Walker

Team Fortress 2 is used by Valve as a testbed to explore new game design ideas and business models, the title’s lead designer has said.
Speaking to Gamasutra, Robin Walker said one of Valve's goals with Team Fortress 2 was to explore new areas to help safeguard the company’s future.

He explained that testing out MMO features and making the game free-to-play allowed the studio to garner a wealth of data on new business models and genres, allowing them to make informed decisions in the future as the industry rapidly changes.
“Our secondary goal with Team Fortress 2 was to see if we could explore specific game and business design spaces that we felt were potentially a requirement for the long-term survival of our company," said Walker.
He added: “When the game shipped, MMOs were the dominant story in the industry, and one concern we had was that we might not be able to survive if we didn’t build one.