What is cheaper than a reserved instance on AWS? How about not running an instance in the first place?

AWS announced a new reserved instance model, designed to save you up to 63% per instance. Most small and mid-sized companies aren’t going to commit for 3 years, so we are looking at something closer to 40% savings. That’s a good start.

However, chances are you are over provisioning - running more and/or larger EC2 instances than you actually need. Let me illustrate this with a few charts. Suppose the traffic to your site follows the usual wave.

Once upon a time, about last Monday, I thought PV AMIs were "the thing". Then I noticed the AWS Web Console had moved the HVM Amazon Linux AMI to the top of the list. I did a little more digging, and found that every 2nd generation instance type can use HVM, but only a subset can use PV. This is the opposite of the 1st generation instances.

Intrigued, I started asking around but no one could say for certain what the future held. So, since I was paying for Business Support anyway, I though I'd ask them. The response from …