As many others I use Microsoft Azure for more and more reasons. Most of my test and demo environments appear in the Microsoft cloud and will be used anytime from anywhere.
The big advantage is the pay-as-you-go strategy. I just need to pay for the resources I really use. My MSDN account gives me the abillity to spend 75$ every month in azure for free 🙂
But on the downside, 75$ are used up very fast and so I just wanted to run my mashines if I really need them.