I had little knowledge about CDNs before but after reading through and trying Prismic and ButterCMS, I found it is very useful. Due to the rise of SPA because of React, Angular etc to name a few, I was looking for a solution to not create a backend and still make the site dynamic so the business user can edit the content.
I found the mixture of using surge with CMS very useful. Another use case is to use it as backend for your native mobile application.
Ship static sites soundly.
A tour of Surge, Static web publishing for Front-End Developers.
On top of all this, Surge is free to use, even with custom domains. Publish your project to a CMS in seconds.
For information, follow this link.
One CMS Backend for all your Websites & Apps.
Some prismic use cases.
I wrote an article on How to use Prismic and Surge to create deynamic websites.