said by thedragonmas:simplified. (i.e. im no network admin). you want to go to google, you type in google.com in your address bar, the browser then requests the IP address from the dns server, the dns server replies with an address. your browser then goes to the address via what ever "path" the ISP selects. the dns can not specify a path.
i.e. you want to call doe, you look up their phone number in the phone book, you pick up your phone and dial, you have no control over what path the phone call takes, the phone company does.
Yes, but the assumption there is that there's one source/server for a particular piece of information, whereas NetFlix/Amazon/Apple have many many servers.
Think of it this way--if one asks directory assistance for McDonalds, there's one a mile away and one in Boise, Idaho. They both serve the same cheeseburgers and the same same soft drinks. However the cheeseburger and drink will be obtained much more quickly by going to the McDonald's one mile away rather than Boise.
In the same way, there are local phone books with information optimized for the people in that locale. One could check a (theoretical) "national" phone book for McDonalds, but the local phone book will give local results. If someone checks a "national" phone book (OpenDNS, Google Public DNS) they're going to receive valid yet unoptimized results due to the lack of geographical information. In the same way, Amazon/Netflix/Apple may try to provide Mediacom's "local" DNS servers with "local" servers for streaming video.
Does it work perfectly? No. In fact I'm not surprised it may have the opposite effect in some cases, but it can have a positive effect. If Netflix can make a customer's video stream that much smoother with a "local" server they may choose Netflix over a competing service.
A related idea--Netflix's "Open Connect Content Delivery Network": »
www.netflix.com/openconnect .