I use RedHat because it does what I want it to do. Albeit not perfectly, but Good Enough. I've paid for RedHat a time or two. I felt it was a worthwhile contribution. I know RedHat's layouts and I'm happy with that.
I've paid for Star Office. I still use it on one or two boxes even though OpenOffice 1.0 is here. I paid for WordPerfect on Linux some years back, too, though I never got it poroductive.
I've paid for Opera several times - both Windows and Linux versions.
I prefer to purchase games I will play considerably. I'm intending to purchase a copy of TransGamingX because I don't want to ever need Windows XP.
I purchased a Debian CD set, and added a donation to the cause. I tried it and it broke. This happened three times. :-/ I'm not willing to have another look at it yet, but I'll be happy to purchase a CD set when I do.
Our major customers run Linux servers because that's what we support to do the job they pay us to do. They don't care what distro it is (most of them don't even know), just that we can support it. So we run RedHat. Because we can support RedHat.
Wade.