Facebook is moving ahead with plans to test a new mobile feature to entice more people to buy products while shopping on smaller devices such as iPhones.There will be two partners for the test: Jack Threads, a men's fashion and clothing site; and Mosaic, a site for turning digital photos into a physical book. The feature, "Auto-Fill with Facebook," will roll out starting Monday night to a very small percentage of people using those companies' iOS apps, a Facebook spokeswoman told the IDG News Service.The tool is designed to take some of the complexity out of the checkout process on mobile. If a user already has his or her credit card information on file with Facebook and is shopping within the Jack Threads or the Mosaic app, a button will appear upon checkout asking permission to access the person's payment information on Facebook. If the shopper says "yes," the payment fields will be filled automatically.Facebook is rolling out the feature slowly, but within a couple of weeks all Jack
