It looks as though Linux users may not be as cheap as some people would lead you to believe. Sure, they use a free operating system, but that doesn't mean they aren't willing to spend money, especially when it goes to a good cause. Data from the Humble Bundle sale show that Linux users spend more, on average, than Mac and Windows users.
For the bundle of games, Windows users spent just $6.22, on average. Mac users spent more, $8.34 on average. Linux users, however, spent close to double that on Windows users, shelling out $11.05, on average. When you look at the average price across the all the users, the average shelled out comes to just around $7.
So, as you can see, there are more Windows users dragging the average down close to the level of the average spent by Windows users. Another good thing shown by the data is that not all gamers are free-loaders. The Humble Bundle includes indie games and sometimes eBooks, music, and other digital goods. Users are encouraged to pay what they think its worth--or what they can afford--to get the collection. Proceeds are split between charities and developers.