How many people are using Ubuntu? It is difficult to get precise numbers so we end up looking for trends.
Up until now we had free Linux stats from gs.statcounter.com.
These are the operating system statistics for Greece for the last year. (I am using Greece as an example. All other countries are also supported). Linux distributions are in red, and reaches up to 1.22% according to statcounter.
Statcounter provides web statistics servers for your website, and they offer the aggregate statistics for free. If statcounter is not generally used for stats at websites at your country, then the stats may not be representative. Also, some users may only access certain popular websites that have their own statistics software, thus those visitors are invisible to statcounter. These are some of the caveats when analysing such statistics.
Let's dig a bit deeper. There is a new statistics service, getclicky.com, which has been running for about a year. The best thing about them is that they also provide statistics between Linux distributions.
Here are the overall operating system statistics for Greece, which can range up to 1.51%.
First of all, it appears there has been a hiccup at the end of October 2012 and start of November 2012, that shows a >12% Linux marketshare; we ignore those two weeks of stats.
In this specific chart Ubuntu is in blue, and has been consistently higher than other distributions. After Ubuntu, the second most popular option is Generic Linux (orange color), which corresponds to browsers that do not reveal information about the operating system through something called the User Agent. Some distributions do not set the User Agent, or if you use some other browser like Chrome/Chromium, then the User Agent does not reveal the name of the distribution.
To check whether your browser advertises your operating system to websites, click on What's My User Agent. If it says
Your User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:17.0) Gecko/17.0 Firefox/17.0
then it advertises your Ubuntu!