This is a post I made on the WoW forums in reply to someone quoting Steam's survey as having less than 2% of people using Linux and saying that that's why big developers aren't likely to support Linux. Here's what I see wrong with that thinking, and also a possible solution to it:
There's something here that should be pointed out. That "less than 2%" is for people actually using Steam on Linux. There's three possible issues here.
1. This one might not be an issue, depending on how the survey works, but it may be possible that Steam running under WINE is misrepresented as a copy of windows. Here's a link that shows that it detects WINE, but it also lists OS as Windows XP: http://anonymousdimwit.blogspot.com/2012/08/steams-hardware-survey-detects-wine.html
2. There are people are daily Linux users, but have a Windows OS for things that don't work well on Linux, such as games. This people of course would be listed as Windows users by Steam.
3. There are people who would be willing to switch to Linux... if there was support. I don't use Windows because it's so wonderful, I use it because games (usually) work with it. *glares at Bioshock 1 sound issues and Bioshock 2 crashing for no apparent reason* I would gladly switch to Linux if I could. That would mean $100+ that wouldn't have to be spent on the OS. In most causes that probably means moving up a bracket with the CPU or graphics card.
The fact they have ANY Linux users listed is kind of amazing. Their selection of games is extremely small.
One thing Steam could do is to add another question or two in their survey.
Something like: What is your preferred OS?
Or something like: If there was more support for Linux, would you use it?
The first question is a bit more fair, while the second question is more so fishing for answers in trying to support Linux. Either way, it may help give better answers to if supporting Linux is acceptable from a business standpoint.