I buy and play an order of magnitude more games these days now that there is a reasonably large library of games on Steam with Linux support. I don't know if it moves the revenue needle for them enough to notice it, but I spent about $10/year on games (sometimes I'd go more than a year between buying a game) before Linux support became a common thing. It's a heck of a lot more than that now, and would be higher still if more games I wanted to play were available for Linux.

I have Windows 7 on my laptop, but my desktop machine (which has a huge video card) only runs Linux. So, gaming happens on Linux or not at all (almost; I play Civ V on my laptop sometimes).