“We haven’t had this kind of transformation since television came in the late ‘40s and early ‘50s,” says Marc Pritchard, the marketing boss at Procter & Gamble, the world’s largest advertiser. Grappling with these challenges, however, may spur a shift in the industry’s structure. There will always be startups, particularly because technology changes so quickly. But on the whole, power is likely to move to fewer, larger companies.”