The year-old iPhone 4S was world’s 2nd most popular smartphone in Q4

We know Apple(s AAPL) sold 37 million iPhones during the fourth quarter of 2012, but a new report gives more fine-grain detail to sales of its top two models. The iPhone 5, which debuted in September, rose to become the best-selling smartphone in the world on the strength of 27.4 million units sold, or 13 percent of all shipments, according to Strategy Analytics’ Handset Country Share Tracker published on Wednesday. The year-old iPhone 4S was the second-most popular smartphone, with 17.4 million units sold. And both models beat out Samsung’s Galaxy S III juggernaut, which after five months of availability, sold 15.4 million units during the fourth quarter.

Credit: Strategy Analytics

Credit: Strategy Analytics

While Apple investors continue to worry that the iPhone’s relatively smaller screen and higher price prevent it from attracting more customers, the iPhone seems to be having one of its best moments. Wednesday’s report follows a previous one from the same firm, published earlier this month, that found the iPhone was for the first time ever the best-selling mobile phone in the U.S.

But what may be more interesting than the iPhone 5’s stats is the sustained popularity of the iPhone 4S, which was released in October 2011. These numbers serve as evidence that a significant chunk of Apple’s customers are more interested in a lower price — $99 with a two-year contract — than the absolute latest in tech and design Apple offers. You could also use it as an argument against Apple making a new model cheaper iPhone, since it essentially already has one in the 4S.

For its part, Samsung is reportedly set to release its follow-up to the Galaxy S III, the Galaxy S IV, in March, so this picture may very well change over the next several quarters.