LOL @ their user base comment
In M$ defence, you pay your licence fee, up front, get yourselfs some cheapo HP thin clients, server 2003 and such, job done and it cost X amount.
Linux, oooh its free, until you run up lots of support bills and waste loadsa time faffing around trying to integrate everything
You pay for it after.
As much as the world hates Microsoft they make a good OS, I have Fedora on my machine and although I'm finishing up my software engineering degree (as in I should be able to use a computer just about) I still cannot reliably work a linux distro, I've yet to get a soundcard working in it
Horses for courses but I still don't think Linux can hold anything over MS as a home user OS