""In terms of numbers we're very confident this is an 8 million plus user base of active users," Chris Kenyon, director of business development at Canonical told InternetNews.com. "That is a hard thing to count and there are lots of issues about methodology for counting but I have seen nothing that sheds doubts on that."
"Other Linux distributions, like Red Hat's Fedora, for example, use the Smolt system, which counts users based on the number of unique IP addresses that get updates. For the current Fedora 9 release, Smolt has counted 1.2 million unique IPs."