Well the title is tricky , but this to draw attention , if you want to serve your customer with excellent customer experience , then you need to have CDNs ;
A content delivery network (CDN) is a large distributed system of servers deployed in multiple data centers in the Internet. The goal of a CDN is to serve content to end-users with high availability and high performance. CDNs serve a large fraction of the Internet content today, including web objects (text, graphics, URLs and scripts), downloadable objects (media files, software, documents), applications (e-commerce, portals), live streaming media, on-demand streaming media, and social networks.
Most CDNs offers a partnership so Telecom or ISP can be a hub or a provider .
if you want to check which site is using which CDN then the best answer is