Apple sold nine million new iPhones in the first three days after the iPhone 5S and 5C hit shelves. The number surpassed first weekend iPhone 5 sales last year by almost four million, although the comparison isn't a strict one, since it pits sales of two iPhone models against sales of just one.

The higher sales numbers may also be less surprising given that Apple launched its new iPhones in two additional markets this time around—one of them China. Last year, first weekend iPhone 5 sales in China totaled upwards of two million units, although Apple didn't launch there until almost three months after it debuted the phone in the U.S., Europe and Japan.

Apple didn't break down individual model sales, but stated that demand for the iPhone 5S exceeded the initial supply, and that many online orders are scheduled for shipment in coming weeks.