For large ISPs, google will send them a rack to put in their facilities, which essentially acts as a cache for google requests by the ISPs customers and reduces

For large ISPs, google will send them a rack to put in their facilities, which essentially acts as a cache for google requests by the ISPs customers and reduces the load on the backbone and/or peering network. See http://blogs.broughturner.com/2009/04/googles-peering-and-caching-strategy.html http://blogs.broughturner.com/2009/04/googles-peering-and-ca...