AT&T has topped the expectations of analysts despite a 15% decrease in earnings in the second quarter. While the economy has seen better days, the carrier shipped enough of Apple’s iPhones to carry it through the quarter. Their dependence on the popular smartphone has brought concern to many analysts, as they wonder what would happen if AT&T lost its exclusivity contract.

AT&T activated over 2.4 million iPhones in the second quarter – more than a third of which were new customers. Gregory Lundberg, an analyst for Commresearch, figures that without the iPhone, the carrier would have seen a 25% decrease in new customers over the first quarter. AT&T said that the June 19 launch of the iPhone 3GS was the best sales day in the history of AT&T’s retail and online stores.

The company added 1.4 million net subscribers in the recently passed quarter, including 1.2 million monthly-billed customers. Analysts polled by Reuters predicted 1.08 million subscribers. AT&T scraped in a profit of $3.2 billion ($.54 per share), compared with $3.77 billion ($.63 per share) in the year ago quarter. This beats earning estimations of $.51 per share.