Yeah I don't get their approach. There is no way this will cause 100% delivery if one server fails within that rotation.

That chances of failure go up dramatically if 2+ hosts behind round robin fail, etc.

Not to mention once hosts resolve this to an IP they will re-use the route. This approach is not balanced.

I don't want to be /that/ guy but if they can't scale with ELB they should invest in a dedicated load balancer infrastructure that can offload requests to their cloud instances.

This is a really bizarre post.