Valve Switching Team Fortress 2 To Free-To-Play Increased Revenue Twelvefold
 

http://gamasutra.com/view/news/16492...eetoplay .php


In June of 2011, Valve Software took its four-year-old online first-person shooter Team Fortress 2 and made it completely free-to-play -- and ended up increasing revenues by a factor of twelve as a result.

In related news, Valve's head honcho Gabe Newell is worth billions. Not bad for a company that rarely releases a game.