That is now, as opposed to then, when the network was announced. Back in 2010, the blog post announcing the network was titled "Think big with a gig: Our experimental fiber network." Google has apparently re-thought the experimental part.
Currently the network exists in Kansas City (both of them) as well as beta test site that was begun at Stanford University’s Residential Subdivision, which is a group of approximately 850 faculty- and staff-owned homes on the campus.
Speaking at the New York Times’ DealBook conference on Wednesday, Schmidt confirmed that Google Fiber is “not an experiment; we’re running it as a business.” In addition, Schmidt added that an expansion should be coming with Google Fiber coming to “hopefully more cities if we’re able to expand our service.”
When asked about a expansion would happen, Schmidt responded: “We’re trying to decide now.”
Real-world testing has shown Google Fiber provides shockingly fast speeds. It has been measured providing 841 Mbps download and 923 Mbps upload. In Kansas City, though, Google is only installing Fiber in residential areas; businesses have to wait.
In a country (the U.S., in case you didn't know) which badly trails a number of others in its average broadband speed, Google Fiber is impressive.