Amazon is pushing retailers to accept yet another digital wallet at the point of sale — its own Amazon Pay, which until now has been used almost entirely in the e-commerce world, according to a report in the Wall Street Journal.

Brick-and-mortar retailers view the Seattle-based commerce giant Amazon as a direct competitor, so this move may not be welcome. Amazon seems to recognize that, and is going to focus its initial efforts on restaurants and gas pumps, according to the report.

Mobile payments as a whole have shown strong growth every year but still not taken hold in the card-loving U.S. In 2018. mobile payments at the point of sale are projected to reach $23.5 billion for the year 2018, compared with $3.7 billion in 2014. Starbucks claims that it is responsible for more than 40% of all such payments.

“To spur adoption, digital wallets need to provide greater value for each transaction,” Danielle Brown, vice president of marketing at the rewards site Points said in RetailDive. Loyalty and rewards have traditionally been the driver of mobile payments, as Starbucks has demonstrated. Amazon can easily deploy rewards for mobile purchases, something Apple, Google and Samsung have struggled with.

Amazon has already indicated an interest in brick-and-mortar, opening Amazon Go stores and bookstores in Seattle, San Francisco, Chicago, and New York. These stores have no checkout counter, but allow customers to make purchases via their Amazon accounts. And of course, Amazon now owns Whole Foods, where Amazon Pay sits alongside other mobile payment options at the checkouts.