Microsoft's Azure is narrowly ahead of Amazon as the biggest host as measured by the number of web-facing Windows computers, according to Netcraft, which runs regular site surveys. As the graph below shows, the companies have been neck-and-neck over the past year. "Microsoft now has 23,400 web-facing Windows computers against Amazon's 22,600," says Netcraft, adding that each has "just over 1% of the market".

So, it's not exactly world domination, and we don't know how many of these Azure machines are running Microsoft services such as Office 365, Xbox Live, Skype, and OneDrive, rather than jobs for customers. These include, says Netcraft, the Sochi 2014 Olympic Games, Aston Martin, BenQ, and McDonald's Happy Studio.

Netcraft speculates that the "Windows Azure Web Sites service -- available to the general public since June 2013 -- may be the driving force behind Azure's growth. This Platform as a Service allows existing applications written in ASP, ASP.NET, PHP, Node.js, or Python to be deployed on an automatically scaling platform without managing individual computers. Microsoft also provides pre-configured software packages, such as WordPress, which can be used immediately with the Web Site service."

Amazon presumably has a huge lead when it comes to Linux hosting, because that represents only 10% of Azure's business, on this measure. More than half of the Azure computers run Windows Server 2008, while about a third run Windows Server 2012. Ubuntu is the most popular version of Linux on Azure, followed by CentOS.

Microsoft has room for expansion because "52% of Azure's web-facing computers are in the United States, 36% are in Europe, and only 12% are in Asia Pacific." Indeed, it should have an advantage in parts of Europe and Asia because Microsoft's own businesses operate in many more countries that Amazon. When Microsoft slashed its cloud storage prices a month ago, it said in an Azure blog post: "We’re also making the new prices effective worldwide which means that Azure storage will be less expensive than AWS in many regions."

Amazon's cloud strategy is to be the low-cost cloud supplier while Microsoft's is to track if not match Amazon's prices while offering better performance. This should be good for customers, if not necessarily the Windows hosting providers who are Microsoft's partners.