Number of GNU/Linux users (and market share)
Charles from StandardsAndFreedom.net blog (proudly hosted by.. er.. Libervis ) wrote an interesting entry: Numbers, Downloads and Straws. He points out that Fedora may have around 9.5 million users while Canonical claims 8 million, though Canonical also ships CD's too. He concludes that considering these top distributions and adding all of the other smaller distributions, GNU/Linux may be second, after windows, in the number of users, leaving Mac only the third place, and this by conservative estimates.
So I suppose it would probably be anywhere between 15 million and 20 million users.
On the other hand, Mac share has been raising lately as well (almost 8% this year) so it seems like GNU/Linux and Mac are pretty much competing for that second place.
What do you think? Do these numbers make sense?