Indie games are not very popular, on any platform. They are independent of the big game companies like EA, id Software, Infinity Ward, and Crytek. Thus they also lack the kind of funding these companies have. Windows users started taking games for granted a long time ago. With Windows being the dominant operating system, Windows users know that high quality commercial games have to have Windows versions, so when an indie game comes out, with an average price of $20, they seem too expensive to most people using Windows. As evidence, the average price Windows users are paying for the recent "Humble Indie Bundle #2" is $6.63.
The same thing can be said about Mac users. Less games than for Windows are developed for the Mac, but there are more games available for the Mac operating system than there are for GNU/Linux. Mac users either aren't heavy gamers or they are taking games for granted just as Windows users are. The average price Mac users are paying for the recent "Humble Indie Bundle #2" is $9.04. This is a higher price, but only by $2.41.
GNU/Linux users seem to have a very different attitude towards games. GNU/Linux is the third platform games are most developed for. If I had to guesstimate, I'd say for every 10 games available for Windows there is one available for GNU/Linux. With this scarcity of games, GNU/Linux users have become desperate.
We're willing to take whatever we can get!
As evidence, the average price GNU/Linux users are paying for the recent "Humble Indie Bundle" is $13.77. On average that is $4.73 more per purchase than the average Mac user pays, $6.01 more per purchase than the overall average, and $7.14 more per purchase than the average Windows user pays.
Seven dollars and fourteen cents! We're willing to pay more than 107% more! More than double the price Windows users pay. And this was true for the first "Humble Indie Bundle" as well, the numbers were a little different though: Windows average was $8.05, Mac average was $10.18, GNU/Linux average was $14.52. So in the first "Humble Indie Bundle" everyone was willing to pay a little more, maybe because the games were more appealing, maybe because the games got "Open Sourced" once they made a million dollars, and maybe the current "Humble Indie Bundle" will see people paying more as it continues to run.
I'm willing to challenge the statistics though. Many people -- such as Minecraft's developer "Notch", "grflwitz", and OnLive -- have paid very large amounts of money (upwards of $2,000) to the "Humble Indie Bundle" and if these people happen to be using the dominant Windows operating system, than such contributions are surely influencing the statistics. There is no way to fix this though, the contributions are surely appreciated by the "Humble Indie Bundle", its games' developers, and the two charities.
These numbers show why all indie games should have GNU/Linux versions. And I think most indie game developers know this, a very large portion of games now have GNU/Linux versions, largely thanks to the "Humble Indie Bundle" where a couple of games have made their GNU/Linux premiere.
Now that the first "Humble Indie Bundle" is included in this current bundle, it's worth buying if you missed the "Humble Indie Bundle" the first time around. I'd suggest buying the "Humble Indie Bundle #2" and splitting your contribution equally between the two charities and the first bundle's developers who liberated their games in the first "Humble Indie Bundle". Click here to get your bundle