AT&T CEO Randall Stephenson related details about how the carrier came to partner with Apple on the iPhone, describing in an interview that the move essentially brought a makeover to the company. "It changed our capital allocation. It changed how we thought about spectrum. It changed how we thought about engineering and designing networks. Suddenly you go from thinking that 40,000 cell sites are sufficient to thinking it's going to have to be multiples of that," Stephenson told Forbes.