AT&T's quarterly earnings revealed that Apple sold 3.7 million iPhones in the three-month frame, and 22 percent of those customers were new to AT&T. The numbers show that the iPhone represented 73 percent of the total 5.1 million smartphone sales during the quarter.
At the end of the quarter, 61.9 percent, or 43.1 million, of AT&T's postpaid subscribers had smartphones. That's up from 49.9 percent, or 34.1 million, a year earlier.
The numbers show that AT&T sold a million more iPhones than rival Verizon in the same quarter. Verizon announced last week that it sold 2.7 million iPhones in the second quarter, as its smartphone penetration among subscribers reached 50 percent.
Unlike at AT&T, where most of the smartphones activated by the carrier were iPhones, Verizon is mostly dependent on Android-based handsets. Last quarter, Verizon sold 2.9 million smartphones running Google's Android mobile platform.
AT&T announced on Tuesday that it added 1.3 million total wireless net additional customers, and that it saw gains in every customer category. Sales of tablets and tethering plans saw 496,000 net additions, reaching a total of 6.3 million — up more than 50 percent from a year ago.
AT&T also saw its first enterprise revenue growth in more than four years. The company reported 66 cents diluted earnings per share, up from 60 cents in the second quarter of 2011, and consolidated revenues of $31.6 billion, growing 0.3 percent year over year.
"We executed well across the business and posted another strong quarter with growing revenues, expanding margins and double-digit earnings growth," said Randall Stephenson, AT&T chairman and chief executive officer. "Our mobile Internet leadership continues, with solid gains in smartphones and tablets, plus our wireless margins have never been better.
"And most impressive, with this growth, we also achieved our best-ever postpaid wireless churn, which points to the premier experience customers receive on our network. All of these things add to our confidence and enthusiasm looking ahead."