Ever heard of the Akamai network? Netflix might be a good example. Trace routes show latency between network hops. To reduce latency you either buy better network hardware, buy better cabling, or reduce hops in n the network. Since the first two are more expensive than the third, if your service must have very fast response between server and client, move the server closer to the client. Large corporations run cache servers in multiple data centers everywhere geographically so the response time for clients is better than their competition. Why new video services struggles to compete with YouTube is in part because YouTube can afford this kind of architecture where a startup cannot. Even if it’s the best code money can buy, it will never provide the same level of experience to users as local cache servers. Kind sucks not body can compete.