Just one day before Google is expected to announced that it will bring Google Fiber to Austin, Texas, two Wall Street analysts from Alliance Bernstein (Carlos Kirjner and Ram Parameswaran) have calculated that it would cost $11 billion annually to bring gigabit to the rest of the nation on the scale of other large nationwide providers like Comcast or Time Warner Cable. Based on that model, Google’s fiber network would pass “roughly 15 percent of US homes.”
By comparison, Google is worth (based on its market capitalization) around $253 billion—so the search giant would have to spend about four percent of its net worth (spread over five years) to bring a fair portion of us some of that sweet, cheap, crazy-fast broadband.
Google appears to be looking for cities that have a certain size (geographic area) and a certain population density—Austin's is roughly the same size as Kansas City, KS and Kansas City, MO combined. Google's aim, after all, is really to sell increasingly targeted ads—Fiber, like Gmail and search, is a means of doing that.