The Google Network Infrastructure page describes their various data center locations. What really stood out was their “Edge Nodes (Google Global Cache, or GGC)” map:
Compare that to the map included in this 2014 Open Networking Summit talk:
I won’t bother trying to count the dots on each map ( and I haven’t been able to find a list of locations any where ), but I think it is safe to say that the number has increased significantly over the last six seven years.
At some point having a data center in your town will be at the same level as having local power, water, and sewer services.