You're completely right, if your workload is even so you can get 15 servers installed and use them all year you're better off using bare metal. However if you

You're completely right, if your workload is even so you can get 15 servers installed and use them all year you're better off using bare metal. However if you have uneven load - say you're in accounting and you need 5 servers most of the time, but 50 in the runup to year end, you will save money in the cloud rather than having 50 servers requiring power and patching and 45 idle. There are also other benefits to doing things in the cloud. When you start treating machines as disposable you're forced to automate setup. When you've automated setup you no longer patch machines - you get a new patched base image, run the setup, then simply replace the old machines.