T-Mobile is offering a BOGO deal on all smartphone until December 20. Mix and match, it doesn't matter which two you select just as long as you activate two new lines. Now, there is something of catch and that is, not all T-Mobile stores are participating in this offer. According to BGR, T-Mobile stores in the Big Apple will be glad to hand over that second smartphone, but locations in LA will not. Some locations will match the competition even if it is another T-Mobile store, so bring proof of the offer and you might get that second smartphone even if the store has no idea what you are talking about. If you're a T-Mobile customer or thinking of switching, let us know if you get to take advantage of T-Mobile's generosity and let us know which two smartphones you picked up.