Sprint on Wednesday stated that it has entered into a four-year deal valued at $15.5 billion to offer Apple’s iPhone line of handsets, the GSMA’s mobile business blog reports. Additional details were not revealed, but the carrier said it expects iPhone-related revenue to outperform the deal. “We expect the lifetime value of a typical iPhone customer to be at least 50 percent – yes, at least 50 percent – greater than a typical smartphone user, driven primarily by more efficient use of our network and lower churn,” Sprint CEO Dan Hesse said during the company’s third-quarter earnings call. Sprint also said it expects to sell more than 1 million iPhone handsets in the fourth quarter of this year. AT&T revealed earlier this week that it activated 2.7 million iPhones last quarter while Verizon Wireless said it sold 2 million iPhone 4 handsets over the same period of time.