Hot on the heels of iPhone 5 promotions from T-Mobile and Verizon, AT&T appears to have thrown its hat into the ring with reports that existing, upgrade-eligible customers are being targeted in a new email. The email offers special trade-in pricing for used iPhone 4S models, promising up to $200 in credit towards the cost of an iPhone 5 -- effectively cancelling out the up-front cost of moving up. Appleinsider reports that the email may be only a regional promotion instead of national.
