Mobile payments account for 10 percent of all Starbucks revenues in the U.S., Mobile Commerce Insider reports this week, and the company’s mobile apps are used by 10 million active customers. And a recent campaign offering a $5 credit to join the My Starbucks Rewards program generated 500,000 downloads of the mobile app within the two-week offer period.

That kind of success is particularly striking because mobile payments at the point of sale continue to struggle mightily. Starbucks has done a brilliant job of making mobile payments easy for customers to understand and use, and its loyalty program is a great incentive to get users to pay with their phones.

As I’ve written before, though, Starbucks is uniquely positioned to leverage mobile payments, and duplicating its success will be very difficult. The company has a massive worldwide footprint, and its affluent customer base is surely more tech-savvy than those of most retail chains. And consumers won’t be willing to fire up a stand-alone app to make payments for every retailer they visit regularly, so vendors who want to encourage mobile payments will increasingly have to choose which mobile apps, technologies and ecosystems to partner with. National retailers should certainly learn from Starbucks’ success, but very few have even a chance to copy it.