The value in today's content delivery systems is largely the value of caching, and the cache technology used is pretty vanilla.
Lets start by looking at what a cache is.
A cache is a computer system that sits in a communication flow, watches what happens, and intrudes when it thinks it knows the answer. The cache has multiplied the bandwidth by a factor of two. The cache is typically much closer to the requester than is the origin server. Flash crowd control. The good and bad news is that the Internet connects you to hundreds of millions of users.