Metrics can be fuzzy but they aren't numbers you pull out of your back
pocket. The source is important and people do notice.
"Shuttleworth also touched upon the issue of Unbuntu's user base, saying
that it has "in excess of 6 million users." He did, however, admit that
he couldn't be sure of the number since there is no formal registration
process for most users, and neither Canonical nor the Ubuntu community
do any active monitoring of installations.
However, Red Hat Fedora Linux, Ubuntu's competitor, provides publicly
available usage numbers based on how many Fedora installations update
As of Oct. 3, Fedora reported nearly 1.5 million users for its Fedora 7
release alone. Fedora had previously reported nearly 3 million users for
its Fedora 6 release. "