CDN, as it is widely known, allows users to download content from the closest geographical point. However it may occur that the CDN provider is not too good represented in a certain geographical location. It may lead to the decrease of download speeds for end users.
How should you behave in such situation? First of all, it is always a good idea to choose from several providers, properly examine their geography, see what resources they have. It may also be good to spread the load over different providers, and in the end such scheme may be rally saving. It will bring more reliability to your project because the chance that your providers will cease to work for some technical reason, is too small, and therefore your project will always be online.
In CDN you may also use the time zone balance, that means that you spread the load and optimize performance of CDN depending on the time of day in different locations. This will allow to avoid problems and slowness in Internet and to get more productivity - it will be very useful and will bring good reputation to your project.
As we have said, there are economic advantages in using several CDN providers. For today there are a lot of providers that you may choose from. The cost of services are different as well, that's why you get a very flexible pricing scheme.