Out-of-home ad giant CBS Outdoor has put up the first-ever 3D billboard ad, reports Brandweek.  The firm has placed the ad for credit card company Visa’s Go World campaign, rolling it out on Monday at New York City’s Grand Central Terminal.  Brandweek says the ad comprises more than 100 pieces of media making up a diorama that runs down a terminal passageway.  It appears in 3D using special glasses, which attendants at the site are providing to interested onlookers.  But the outlet adds that it’s designed to be visible without glasses, appearing dimensional to the naked eye.   The ad is on display through the end of February and is expected to engage as many as 70,000 people a day.  Read more at Brandweek {link no longer active}.