So, now we know where all those disgruntled Sprint customers have been going. In total, 2.4 million people joined T-Mobile USA's network in the first quarter of this year, with around half of those opting for the carrier's "Un-carrier" style plans, which do away with service contracts and instead provide straight-up financing to those looking for a new handset. Despite being reprimanded by an industry watchdog for its aggressive and not-wholly-accurate marketing, T-Mo actually managed to beat its last bumper quarter in terms of new subscribers, at a time when the other, bigger networks saw much smaller increases -- AT&T and Verizon each only added around half a million new postpaid customers last quarter, for example. Curiously, on the financial side of things, T-Mobile actually reported a drop in earnings -- which it blamed on the fact that it's having to expand so quickly. Another curiosity: If some of this growth really has been happening at Sprint's expense, then pretty soon it may not matter.