A very important point: lots of statistics are based on SALES of OS licenses. They are usually called "OS market share". You don't need to be a genius to understand then that only a small subset of the actually Linux-running computers are counted: the one's running an official, registered copy of RedHat or Suse or so. As Linux is a free software, it is also (most of the time) gratis, so its "market share" is, by definition, 0.

This leads to FAKE STATISTICS such as the one in the picture below, that pretends that Linux is more or less running on 2% of the total amount of computers, while it is actually above 90%.

Aside of that, huge amount of computers are buy WITHOUT a bundled OS, as the law actually allows. But stupid supermarket customers do not know that and think a computer MUST BE DELIVERED with a pre-installed OS. However, lots of PCs are re-installed with Linux or are used in dual-boot mode under Linux.

In the professional market, you can get any server without OS (or with Free-DOS, for tests purpose) and that's great. I REFUSE to buy or sell a computer, if it's bundled with a software license, because this is ILLEGAL. And my business runs well.

If you count the ACTUALLY Linux-running computers (including Internet-enabled TV sets, set-top boxes, vDSL modems, cars, satellite receivers, MP3 players, smartphones, tablets, routers, web servers, firewalls, WiFi access-points, IP cameras, washing machines, PLCs, IP phones, ... then more than 90% of the CPUs existing in the world ARE RUNNING LINUX. Everywhere. Everyday. For any purpose.