Smartphones and tablets now generate 6.8 percent of all digital traffic in the U.S., with mobile phones responsible for about two-thirds of that traffic, according to new data published by digital research firm comScore. Interestingly, Wi-Fi connections account for 37.2 percent of U.S. digital traffic over mobile phones,  up 3 percent over the last three months. At the same time, tablets are driving mobile broadband access, with close to 10 percent of tablet traffic originating on devices powered by a mobile network connection. Article