Also, from a slightly different angle: as an ISP, if I've been paid by either the source OR the sink in question, then I don't charge anyone else. I might get lucky and be on both sides of the equation, maybe I might have both of them as customers, which is great for me, as an ISP.

But if I don't, if I've been paid to carry that traffic by only one of the two sides, I have the responsibility to fulfill my commitment to do so. I made a promise, and I charged money for that promise. Even if it was a bad decision on my part, I still made the promise.

Normally, when I'm only one side, I don't have a link directly to the other end of the connection. I'll have to buy service from a third party to make the connection, and the other side of that link will also be paying some transit provider to get the bits there.

If we're lucky enough that we can link directly with each other (and if we have enough traffic to make it worthwhile), then that's normally a free exchange. I was paid for one side, you were paid for the other side, let's swap the bits for free... why pay Level 3?

Suddenly asserting that I'm required to pay you in order to reach your customers is total crap, since we're supposed to be peers. The source and the sink are of equal importance.

As Comcast, getting the Netflix data for free is a huge benefit to them. They should be forced to buy that data from some transit provider, and instead they're getting it for nothing. Netflix will actually show up in most reasonable sized networks with a bunch of caching gear so that you can deliver their stuff without having to pay anyone. They do this because it saves them money, but it saves you money too! The source and the sink are equal.

Only in a messed-up monopoly environment can the sink posture and insist on getting paid twice for doing what it was already paid to do.