Features limited to the iPhone 7 Plus helped boost sales of the larger smartphone, but they were not the only reasons why a higher percentage of customers went big last year, analysts said.

“The nature of the market is also shifting,” said Ben Bajarin of Creative Strategies, in a recent interview. As consumers encounter large-screen smartphones with more frequency — especially ones owned by friends — there’s a bandwagon effect, he explained.

Although the shift to bigger screens has been strongest in China and other Asian markets, the iPhone 7 Plus accounted for a larger proportion of new iPhones sold in the U.S. as well, said Bajarin, citing his firm’s research.

Apple does not separate iPhone sales by market, or even say exactly what percentage of total sales was of the 7 Plus, but CEO Tim Cook did claim that the number was the highest yet for its 5.5-in. model. “We saw especially strong demand for iPhone 7 Plus, which was a higher portion of the new product mix than we’ve ever seen with Plus models in the past,” Cook said during the December quarter’s earning call on Jan. 31.

than its 2015 and 2014 forerunners.

That was, in fact, the case: The December quarter’s iPhone ASP was $694.57, a record.

Some credited the iPhone 7 Plus’s performance to the features Apple offered only in the large-screen model, notably Portrait Mode. Bajarin agreed that Plus-only features could be selling points. But they were no guarantee. Those specific to the iPhone 6 Plus and 6S Plus, for example, weren’t enough to make those models as successful as the 7 Plus.

More telling than differences between iPhone models, he said, was the consumer perception of the total package. “The evidence we see from China is that when something [is seen to be] the pinnacle at that moment, that’s when China moves toward that product,” Bajarin said. “So there is some value in keeping interesting and expensive technology as a differentiator.”