Sometimes the distance produces latency, but most of the time ISP’s cap single connections, as part of their ongoing peering battles or so that their users don’t eat up all of their bandwidth watching Youtube. Here’s a good article about what’s been going on behind the curtains: http://arstechnica.com/information-technology/2013/07/why-youtube-buffers-the-secret-deals-that-make-and-break-online-video/ and here’s another one: http://blog.level3.com/global-connectivity/observations-internet-middleman/