A CDN is not just about Latency - Why it is always better use a CDN.

CDN or content delivery networks are now everywhere. Every second site that you visit are fully or partially served by a CDN.

But why do you need a CDN ?
The major use of CDN is to reduce latency. A regionally diverse CDN can serve pages from a location nearer to the user thereby reducing the latency.

So you think you don't need a CDN because you are not serving VOIP and do not require such a low latency ?

The answer is No.

Latency is just one of the factors for using a CDN over a single datacenter.

CDN also reduces your overall running cost. Specially for sites that are very large in size with a large number of visitors (in the millions), CDNs reduces the overall cost of maintainance.

Because, with the current day technology, it is extremely costly to serve high data rates from a single location. The locations may not have sufficient technology and know how for serving such a huge bandwidth. Setting up such an infrastructure requires expertise that is difficult to find and costly.

With a distributed CDN, the traffic is divided accross different nodes, each location now needs to serve only a reduced number of users. This reduces the complexity of infrastructure that is required at each location.

Also a CDN allows you to easily add extra nodes to the network. Specially when the traffic spikes, you could add another CDN at a different location and this enables you to cater to the new increased traffic easily. But if you were using a single datacenter, then it usually would mean getting expensive cables and huge setup fees that would mean long term contracts.