Google probably has SOME connectivity they pay for, but by now they are effectively their own Tier 1 network, considering how much Internet traffic flows to the

Google probably has SOME connectivity they pay for, but by now they are effectively their own Tier 1 network, considering how much Internet traffic flows to their servers. They have a 2-byte ASN, which basically means they're a major backbone network. ISPs drool at the chance to peer with Google and get tariff-free YouTube/Google traffic, which probably constitutes a significant chunk of their overall volume. Considering that Google has all of these little mini-datacenters spread throughout major colo facilities, a ton of the edge-to-edge traffic probably flows over in-building GigE or 10GigE. It probably costs them a penny per TB delivered to a peered ISP rather than $.05/GB us peons pay at the colo. The ~8mbit multi-T1 connection at my office amounts to about 38 cents per gigabyte in or out if we use it at 100% capacity 24/7/365. That's still more expensive than the 250GB capped Comcast user, who's effectively paying about 20 cents per gigabyte.