U.S. Smartphone Use in 2015 | Pew Research Center's Internet & American Life Project

From a Pew Research "smartphone-dependent" market profile

"The traditional notion of “going online” often evokes images of a desktop or laptop computer with a full complement of features, such as a large screen, mouse, keyboard, wires, and a dedicated high-speed connection. But for many Americans, the reality of the online experience is substantially different. Today nearly two-thirds of Americans own a smartphone, and 19% of Americans rely to some degree on a smartphone for accessing online services and information and for staying connected to the world around them — either because they lack broadband at home, or because they have few options for online access other than their cell phone.

Indeed, 7% of Americans own a smartphone but have neither traditional broadband service at home, nor easily available alternatives for going online other than their cell phone."

U.S. Smartphone Use in 2015 | Pew Research Center's Internet & American Life Project