Today's Internet is a lot different from itself several years ago. Customers use it to transmit video, video-chatting and conferences, listening to music, talking, photo and video watching and visiting graphically loaded websites and using different web-applications. Such things usually require wider bandwidth than usual browsing or working with email. Today we are waiting from Internet more than earlier.
The surveys show that users in general wouldn't wait for the content to load more than 3 seconds - 40% of them will leave after this time. Every 0.1 seconds of additional site loading results in 1% of losses in sales. Customers don't want high loaded sites.
According to survey the CDN market is going to evolve in several years. In April it was stated that the CDN market in the USA will grow up to 12 billion USD until 2019 - therefore it will more than triple from the level of 3.71 billion of dollars in the year of 2014.
It is natural that the optimization of content delivery is the most important thing for any company because the growth in this sector will mean that the clients will be less and less tolerable to the long loading of the websites.