T-Mobiles Uncarrier strategy is working. Thats around 2.7 million more than ATT managed, and 1.7 million more than Verizon. Its growth over the most recent quarter also reached record highs, with almost 2.4 million subscribers added in the past three months alone, more than ATT and Verizon combined. Despite its rapid growth, T-Mobile is still massively behind its larger rivals.