They previously didn't have to pay Level3 because Comcast and Level3 worked out a peering agreement that assumed general parity of inbound versus outbound traffic, and neither one had to pay. Now that Level3 is serving up Netflix content, the traffic Level3 is sending into Comcast's network is much greater than the amount coming out of Comcast onto Level3. They need a new peering agreement, and this one is going to have to address the imbalance in traffic.

Very very well explained VGPowerlord. I wish I had mod points. Instead, I'm giving you my first comment in some number of years. Use it wisely. Or not. Anyway, your description of Akamai's distributed nature brought it further together for me. Comcast's mistake has been in letting this seem like they're targeting Netflix traffic specifically. If it's a content-agnostic peering agreement they're after (and I hope it is), then it makes total sense. When it seems like they want to make a special fee specifically for Netflix traffic is when it seems anticompetitive.