Not the only reason: http://blog.wolfire.com/2010/05/Linux-users-contribute-twice...
Linux users seem (or seemed in 2010) to have money to burn on games (and charity).
Linux users seem (or seemed in 2010) to have money to burn on games (and charity).
Can anyone explain this?
Fewer games means they're willing to spend more per game;
They want to create an incentive for game devs to port their games;
Linux users are older on average, therefore have more disposable income.