Ubuntu is one of the most popular GNU/Linux-based operating system, along with Linux Mint. Ubuntu started off as a great operating system which, with the help of LUGs and communities, became extremely popular.
However it’s not an easy task to crack the desktop market dominated by Microsoft – that’s one of the reasons why both SUSE/Novell and Red Hat decided to leave the desktop space and focus on enterprise.
Canonical started off in the same year when Facebook started and is still struggling to get a hold of the market.