Great list. It really is quite amazing how cheap it is to build and test SaaS products today. As another data point, my company is two years old, with hundreds of thousands of users and very healthy revenue, and our monthly hosting bill is less than $200/mo.
It's because of services and tools like this that I think bootstrapping will become the norm rather than the exception in the startup world in the future.
If software is eating the world, surely it will continue to eat away at the capital requirements to building and scaling these SaaS businesses.
