I have been working with AWS for over a year, setting up EC2 instances, domains, ELBs, etc. When I want to assign a subdomain to an EC2 instance, I have to create an elastic IP (that I pay for), then assign a CNAME record to that elastic IP. When I want to assign a subdomain to an ELB (load balancer) instance, I just create an alias resource record set to the ELB. I've read over the docs and don't understand why AWS doesn't support aliasing to instances. Am I missing a key concept here? Wouldn't it be simpler to just alias EC2 instances and skip the whole elastic IP bit?