AT&T could lose up to 6 million iPhone subscribers, or 40 percent, if Verizon becomes an iPhone carrier in the near future, says Davenport & Company analyst Drake Johnstone. "Over the past several years, AT&T indicated that 40 percent of its new iPhone customers came from other carriers," the analyst notes. Since AT&T has roughly 15 million iPhone subscribers at present, the 6 million figure emerges as a known quantity of people who have another carrier as an option.
