Focus on project not the hardware
Don’t spend your time trying to ensure that you have sufficient computing power and SAN storage to handle the ever growing number of development and test environments.
No delays and plenty of capacity
Your company needs to provide application development and delivery environments quickly. Often times there may be significant delays getting these environments provisioned, the infrastructure needed is expensive and there is a shortage of available capacity.
Build and deploy
Using Amazon Web Services allows you to provide environments quickly, change them as required and scale up to meet performance requirements. When no longer needed just remove them.