CDN is good for virtually any project and will help to increase speed but not all projects need such service. It is necessary to understand how CDN works and whether the additional costs are worthwhile.
In general CDN is a system of servers geographically spread all over the world. Every such server caches images, JS/CSS files and other structural components. Most of response time usually goes to downloading such content and that’s why caching it is always good in as many POPs as possible.
When the user addresses your website, the statical content is provided with POP that is closer to him, that reduces latency and makes the site load more quickly.
Thus the main reason for CDN use in speed increase – this interests any user. Let us see the example. Imagine the website that is hosted in a certain region and the users that want to access that site, but are located in a far away region. In case the website is located in the Northern America, and the users in Europe, the response speed for them will not be that high in comparison to the users from North America.
Global CDN service will help users from Europe to load static content from closer POPs. This will reduce load times. It is necessary to say that not only CDN helps to increase speed, it also helps to prevent the crash in case of high traffic loads. CDN allows to distribute this load across multiple servers.