It took a mere five years for Uber to reach 75% of the population in the United States, but reaching the other 25% could take a hell of a lot longer. According to senior policy adviser Nicole Benincasa, the remaining 25% of American live in more rural areas that are much harder for Uber to operate in, which is why the company is choosing to put more focus on expanding its other services, like UberPool and UberRush, rather than trying to cover the entirety of the United States.