It's official: The iPhone is a recession-defying powerhouse, fueling strong quarterly results for both AT&T and Apple.

AT&T, which pays Apple about $300 for every device sold, added 1.2 million wireless subscribers, ending the quarter with 78.2 million. That propelled its first-quarter profit of $3.13 billion, or 53 cents per share — topping analysts' expectations of 48 cents per share.

High-profit mobile data usage jumped 39 percent to $3.2 billion. Text messages more than doubled to 94 billion. The iPhone drove much of that traffic.

AT&T said it signed up 1.6 million iPhone customers in the quarter, more than 40 percent of them new to AT&T.

Apple had its best nonholiday quarter: a 15 percent jump in second-quarter profits that beat Wall Street expectations. Sales of iPhones more than doubled, to 3.79 million, from a year ago.

That helped the company earn $1.2 billion during the second fiscal quarter, or $1.33 per share. Revenue grew 9 percent, to $8.16 billion, easily surpassing what analysts predicted.

Many AT&T customers are coming from big rivals like Verizon, which have been unable to stop the iPhone juggernaut. These customers spend about 1.6 times more a month than other customers.