AT&T on Wednesday reported its best-ever first quarter, owed in large part to the iPhone. The cell carrier activated 2.7 million iPhones in early 2010, or 1.1 million more than it did a year ago. It would potentially have lost customers otherwise, as it added a net 1.9 million subscribers that in itself was a record for AT&T and gave it 87 million total cellphone customers.
