Scott Cleland: Google Using 21x The Bandwidth They Pay For → Google and Peering

The peering model only works if your content equals the number of eyeballs you provide. That way your input equals your output. That is why the large ISP's work on a balance of the two. Google should not be peering anywhere - they provide all content, and not one bit of eyeball presence (not including corporate use). Unfortunately somebody has to pay for that usage - and it will be the consumer.