AT&T sold 9.4 million smartphones in the fourth quarter of 2011, but 7.6 million of which were iPhones, the company reported today. According to those numbers, the iPhone made up a whopping 80 percent of AT&T's smartphone sales for the quarter, and 66 percent of all postpaid phones sold through AT&T.

These numbers place AT&T as the biggest iPhone retailer, besting Verizon's 4.2 million iPhone activations and constituting over 20 percent of Apple's 37 million sales worldwide last quarter.

The proportion of smartphone sales is surprising, given that worldwide sales of feature phones began to decline only six months ago after growing for two consecutive years. The big quarter for iPhones on AT&T can largely be attributed to the launch of the iPhone 4S, which also helped iOS even up the score with Android in its percentage of sales to recent smartphone acquirers.