I think that the title is misleading. It implies that when Microsoft needs a server to run some service, they use AWS. The article is a bit vague, but I don't

I think that the title is misleading. It implies that when Microsoft needs a server to run some service, they use AWS. The article is a bit vague, but I don't think it's the case. AWS supports running Windows Server on their servers. You have to pay a little bit extra (compared to running e.g. a Linux kernel from a free distro like Ubuntu). I don't know what the details of the arrangement between Microsoft and Amazon is, but Amazon couldn't just offer Windows Server without licensing it from Microsoft. What is most likely happening is that the surcharge that Amazon collects for Windows Server is remitted to Microsoft. So when the Microsoft guy quoted in the article talks about Amazon and Microsoft being partners, he doesn't meant that Microsoft uses AWS to run their services but that Microsoft licenses Windows Server to Amazon so that Amazon can offer it as an option in EC2.