Black Friday is a peculiarly American (pick one) obsession/ritual/malady/boondoggle. But shopping clearly is not. And the centrality of the mobile device to e-commerce is even truer in some non-U.S. economies. To wit: m-commerce site developer Mobify surveyed 19,000 shoppers around the globe to determine how much of electronic buying is going on from handsets globally. In the U.S., 15% said they have purchased items from their smartphone and 9% have done so from a tablet.