I didn't realize how many "tentacles" Microsoft had until I read this.http://en.wikipedia.org/wiki/Microsoft
Here's an especially interesting quote from near the bottom of that page:
The "Get the facts" campaign argues that Windows Server has a lower TCO than Linux and lists a variety of studies in order to prove its case. Proponents of Linux unveiled their own study arguing that, contrary to one of Microsoft's claims, Linux has lower management costs than Windows Server. Another study by the Yankee Group claims that upgrading from one version of Windows Server to another costs a significant fraction (a quarter to a third) of the switching costs from Windows Server to Linux, even for large enterprises, and that the other major reasons for a switch away from Windows servers were the increased security and reliability of Linux servers and a chance to escape the Microsoft "lock-in."
In 2004, the Advertising Standards Authority (ASA) of the UK warned Microsoft that an ad from the campaign which claimed that "Linux was ... 10 times more expensive than Windows Server 2003", was "misleading", as the hardware chosen for the Linux server was needlessly expensive. The ASA's complaint was that "the measurements for Linux were performed on an IBM zSeries [mainframe], which was more expensive and did not perform as well as other IBM series." The comparison was to Windows Server 2003 running on two 900 MHz Intel Xeon CPUs.