Ah, but WILL... WINE. For isntance, I buy AAA titles, but I dont have a copy of windows to my name anymore - I'm a linux user buying retail games (okay, from the local trade in store ). Though this is also true for Mac I believe that WINE is currently more popular on Linux than Mac. And heres the interesting thing: after a little WINE tweaking I get higher frame rates on Linux with WINE in most of my games than I do on windows... Interesting

Linux is great for network gurus, uber geeks and your "free" thinkers, but it's useless for commercial gain. Unless you are are using it for IT purposes.
This I believe to be debatable though. Yes, the market share of AAA titles sold to linux users and other mianstream software is teeny tiny. In that sense of commercial gain Linux has lost and as much as I hate to admit it, I dont see it catching up with Windows. However look at the kernel - theres IBM, Intel, Sun and every other big comapnys' code in there. Simply because its a more flexible platform - thus it was easier to pay people to contribute to the linux kernel than go out and make an in house product or modify existing alternatives. In this sense, Linux was of massive commercial gain to the R&D teams working all the 'new stuff' coming out today.

Then theres the fact that distros now seem to get sponsorhip from search engines based on how much search traffic they get from that OS. eg. Mint & duckduck go. Same story here as what is happening with firefox versus chrome: it is, at the moment, in googles' interest to not mess up relations with mozilla - since if mozilla sets their default search engine they get more queries on which they can display ads. (this one isn't my point, I read it in a ff vs chrome debate type article ). Or you could look at the VPS route everyone on the internet is now rolling out - especcially those on large infrastuctures (eg Amazon eucalyptus bucket E2/3 thing) and those on very limited plans (linode type services for hackers, small companies and so on). These people rely on the fact linux is as versatile as it is to make their products viable and sell in those rather niche/extreme markets.

So when it comes down to it - yes, Linux people dont directly buy products from companies and thus its not of massive commercial gain to the sales people. But when you look at the fact that Linux is responsible for entire markets on which a large portion of the world wide webs and infrastructure we now take for granted - as well as all the trade that generates - supporting the Linux folk becomes far more attractive.