For mobile payments, women use Starbucks app, college kids use Venmo (chart)

There are hundreds of millions of smartphones in the U.S. but just a small portion use apps to pay for things. That’s despite the efforts of web payment giants like PayPal(s EBAY) and the ubiquitous Google(s GOOG), who both operate mobile payment platforms that are still looking for better adoption.

Onavo Insights gathered data about payment app use in the U.S. from several million iOS and Android users of the company’s mobile data utility apps. The company shared with us what it found out about how mobile payments apps and platforms have grown in the U.S. over the last year. It’s not a complete picture, but it gives a sense of how these apps are faring among smartphone users.

Here is the reach of what Onavo found to be the most-used mobile payments apps in use in the U.S.:

And here are their retention rates among the people who’ve tried them:

Things to note:

  • Starbucks(s SBUX) is the clear winner. But its app is not only used for payments — it is used to download free songs and apps, find stores and see menus as well.
  • Still, people are spending money in the app — of the $500 million spent through mobile apps last year in the U.S., the “vast majority” was through Starbucks mobile cards, according to earlier data shared by Berg Insights.
  • Venmo may have a small audience, but it’s growing (doubled use in June) and the audience is showing loyalty. And that audience is mostly young people, according to Onavo. It stands out from other payment apps, like Starbucks and PayPal, which are most popular among users between 25 and 34.
  • Mobile payment use is higher among men for all the apps listed, except for Starbucks, where women make up 54 percent of users. Square Wallet has the lowest ratio of female users at 21 percent.
  • The biggest carrier-advocated mobile payments platform has yet to launch nationwide: Isis will start rolling out to all U.S. locations later this year and be available on multiple mobile platforms, including iOS, Android, Blackberry and Windows Phone. That will be one to watch.