Apple’s biometrically secured digital payments platform continues to attract new users, according to a new analysis from Loup Ventures.

The venture capital firm had estimated in August of last year that Apple Pay had attained 31 percent of active iPhone users; now, after assessing data points from Apple’s December 18th earnings call, the firm says that number has reached 43 percent of global iPhone users. That would translate to about 383 million Apple Pay users, a 135 percent jump year-over-year. And meanwhile, total transactions exceeded 1.8 billion, doubling over the previous year.

Further clarifying the picture, Loup Ventures’ latest analysis estimates that only 12 percent of Apple Pay users are in the US, despite an estimated 21 percent of active iPhone users being in the country. One of the factors cited by Loup Ventures in this discrepancy is the broader support for Apple Pay on public transportation systems in places like Japan, China, Russia, and the UK; though America’s relative lack of support for contactless payments is likely playing a role here, too.

It still isn’t clear what kinds of revenues Apple is deriving from its payments business, or whether it’s even profitable – Apple has always been tight-lipped about this aspect of Apple Pay – but the numbers certainly suggest that Apple Pay is an increasingly important part of its overall business, even if it’s still a small one. And they point to the broader growth of mobile payments platforms in general, as a growing number of consumers rely on their smartphones for various everyday activities.

Source: Loup Ventures