said by SylphFi 
:They are doing it so they will have their own pipe, and can stop paying someone else (Global Crossing, MCI, et al) to deliver their goods. They are doing the same thing inside the U.S, buying dark fiber between their data centers, so they can cut out a large amount of recurring bandwidth costs.
This having their own Backbone can also be looked at a defense against those ISPs pushing the "Google is a Freeloader" Anti-Network-Neutrality chant. By peering with the ISP (as opposed to doing the peering 2nd hand [due to needing an Upstream Peer to do the actual peering]) they can reach a Peering Agreement that takes the wind out of the Freeloader Bovine Excrement claims.
