Target has launched Cartwheel, a Facebook app that allows shoppers to search for savings, buy items and share deals with friends. Coupons are condensed to a single barcode that can be printed out or scanned from a smartphone. “The benefit from a technology standpoint is that you don't have to carry around paper with you. You don't have to look through the circulars,” said David Schuff, an associate professor of management information systems at Temple's Fox School of Business.