http://www.datacenterknowledge.com/archives/2012/06/05/netflix-rolls-its-own-content-delivery-network/
BT congestion to get a lot worse?
Inevitably... :(
If they have any brains they will look at adding their own "backhual" like Google is/was. Although I don't know if anything good has come from that with Google, so here's hoping!
PS, at least that's how I understood it. I may have got the wrong end of the stick, or shall we say "wrong end of the line". :P
Gioogle laid their own submarine cables to connect their data centre networks to avoid renting capacity from other providers (as IDNet do with BT to deliver your broadband service), not sure if Netflix are doing this yet but they did recently have ports activated at LINX.
What is pictured is a caching server which can be placed at an Internet Exchange Point or placed at a DC of an ISP's choosing that they can phyiscally connect their network to.