Apple's iPhone 5s and 5c seem to be very popular with customers. Last month, Sprint sold a record 1.4 million iPhones in Q3 2013, allowing the company to get closer to profitability for the first
time. Now, T-Mobile has reported that it has sold nearly 550,000 iPhones in this third quarter of 2013. The 550,000 iPhones sold account for about 10% of the company's total 5.6 million smartphone
sales. That includes all of the prepaid devices the company sells, as well as MetroPCS branding phones.