Facebook shares rise on retailer boost Facebook shares rose Friday after it expanded the roster of retailers that let users buy and send items to their friends on its website, as the owner of the world's biggest social network pushes into e-commerce. Facebook is seeking fresh ways to make money from its more than 1 billion users as sales growth has slowed. Since an initial public offering in May, the shares slipped 42 percent as Facebook has struggled to convince investors it can boost advertising sales as more users access the service on mobile devices while also grappling with competition from Google, Yahoo and Amazon.com.