Apple's iPhone may have kept 400K customers from leaving T-Mobile

A new study out from Consumer Intelligence Research Partners estimates that between 300,000 and 400,000 total customers who would have otherwise left wound up staying with T-Mobile in the wake of the iPhone's launch on that carrier. According to The Wall Street Journal, CIRP's estimate is based on a survey of 500 phone activations occurring between April and June, with about 75 of those phone activations being on T-Mobile.

Even when the carrier didn't officially offer the iPhone, T-Mobile was somewhat reliant on Apple's handset. As many as one-in-five of T-Mobile's customers were using unlocked versions of the iPhone on the carrier's network. A survey of T-Mobile's customers found that, among those planning to change devices in the coming year, fully 28 percent planned to upgrade to an iPhone.

Following the device's launch in April, T-Mobile touted a "gangbusters" first day of sales, and there were reports of customers lining up outside of T-Mobile stores to get their hands on the iPhone 5. In the first month after launch, T-Mobile reported selling more than half a million iPhones.

If T-Mobile manages to slow, stop, or reverse customer migration, it would signal increased competition in the wireless service segment. So far, T-Mobile's competitors have continually benefited from the carrier's struggles, adding those customers that T-Mobile regularly shed. The addition of the iPhone, though, as well as novel mobile plan pricing structures, have given the fourth-largest carrier a somewhat better chance to compete against its much larger competitors.