Facebook is testing a new mobile payments feature called Autofill that enables consumers to use payment information they have stored with Facebook to buy products and services via mobile shopping apps.  The test is designed to make it easier and faster for consumers to make a purchase via a retailer’s mobile app, Facebook says. It would also provide Facebook with more data about consumers that would help the social network better target ads, some experts say.

Facebook is testing the feature with men’s apparel retailer JackThreads.com’s mobile shopping app and the Mosaic photo book app. JackThreads.com is fertile ground for mobile commerce app testing. The e-retailer is No. 88 in the newly published Internet Retailer Mobile 500 with estimated 2013 mobile sales of $37 million. 50% of its web sales come from mobile devices, and 90% of its mobile sales come through its apps, mostly the iPhone app, the company says. JackThreads.com declined to comment on the Autofill feature.

The Autofill option appears as a button during checkout if the participating retailer’s app detects through a link with Facebook that the shopper has registered payment information in a Facebook account, Facebook says. Consumers can store credit cards, debit cards and Facebook gift cards, and billing information. Facebook members currently can store payment information via the Facebook Gifts feature.

The Autofill service is not part of a broader plan to become a payments processor, a Facebook spokeswoman says. Facebook is planning to work with payments processors including Braintree, Stripe and PayPal for the service. JackThreads.com and Mosaic both use Braintree, which was recently purchased by eBay Inc., which owns PayPal “This product is simply to test how we can help apps provide a simpler commerce experience,” the spokeswoman says.

Arkady Fridman, a senior analyst at mobile payments consulting firm Aite Group, says the move could give Facebook more information about what consumers are interested in, thus enabling it to make advertising via the social network even more targeted.

“In the long run, Facebook can improve ad conversion by learning when certain users are more likely to buy,” he says.  And that’s on top of the wealth of social data it already has, he says. “This will put Facebook in even closer competition with the likes of Google for ad dollars,” Fridman says.