Eighty-eight percent of Fortune 500 companies that were around in 1955 no longer exist today. Industries get disrupted. How’s that working out for advertising? Until relatively recently, the ad industry has been dominated by the same media that dominated it in1955: print, radio and TV. Only TV is still on top today, but its grip on media buyers is slipping. It’s hanging on by its fingernails. That’s about to change.