Facebook mobile growth accelerates down open road

Facebook mobile phone
Chris Ratcliffe | Bloomberg | Getty Images

Facebook's mobile growth is accelerating down an open road. The social-media giant said fourth-quarter revenue from advertisements on smartphones and tablets increased a whopping 81 percent over the prior year, accounting for most of the quarter's $5.8 billion in top-line sales. With more firms getting comfortable touting their wares on digital devices, Mark Zuckerberg's creation has plenty of room to rumble.