Comment by bcater

FWIW, I worked at an online advertising company that ran a whole division on EC2 machines - at the peak, nearly 100 instances. This was never a problem for us because we were judicious in our use of the machines (minify your content!) and we were disciplined in our deployments and management. If you go that route, just be sure the learn and follow best practices - you'll save yourself quite a lot of time.