The 300,000-400,000 figure comes from a survey of 500 phone activations between April and June, 75 of which were on T-Mobile. Prior to offering the Apple iPhone on the nation's fourth largest carrier, T-Mobile had been promoting its network and unlimited plans for unlocked iPhone users. In the quarter following the April debut of Apple's iconic device on T-Mobile, the latter sold more than half a million units of the phone.
Now that T-Mobile reps can point to an iPhone of the carrier's own, there is no longer the fear that customers will bolt to another operator just because of the still-popular handset. Can T-Mobile use this momentum to make a move toward the nation's third largest carrier, Sprint?