The most popular mobile payment app is…

When it comes to using mobile payment apps, most customers are launching their Starbucks’ mobile app.

The coffee giant’s app remains the most popular proximity mobile payment app, staying ahead of Apple Pay, Google Pay and Samsung Pay. It is also projected to keep its crown over the next few years, according to eMarketer’s latest forecast on U.S. proximity mobile payments.

This year, 23.4 million people ages 14 and over will use the Starbucks app to make a point-of-sale purchase at least once every six months. That puts it slightly ahead of the 22.0 million people who will use Apple Pay, Google Pay (11.1 million users) and Samsung Pay (9.9 million). This ranking will remain unchanged through 2022, according to data.

According to data, Apple Pay, which has the second-highest adoption rate, is currently accepted at more than half of U.S. merchants. Google Pay is not as widely accepted, but it benefits from being preinstalled on Android phones. While Samsung Pay has the lowest adoption in terms of users, it is the most widely accepted by merchants.

“[Starbucks] has gained traction thanks to its ability to tie payments to its loyalty rewards program,” said eMarketer forecasting analyst Cindy Liu. “For users of the app, the value of paying with their smartphone is clear and simple—you can save time and money at the register, all while racking up rewards and special offers.”

As other retailers increasingly create their own payment apps, “they can also build in rewards and perks to boost customer loyalty,” Liu said. “This allows them to capture valuable data about their users.”

The timing is ripe to launch these apps as the number of U.S. proximity mobile payment users will grow by 14.5% this year, reaching 55.0 million. In 2018, for the first time, more than 25% of U.S. smartphone users ages 14 and older will make a proximity mobile payment at least once every six months, the study reported.