CANNES, France — The move from a desktop digital world to one that is mobile is forcing advertisers to work harder than ever, says a veteran digital media exec now at an Media Rating Council-approved mobile ad serving company.

“Delivering in to mobile is about 20 times harder than it is in desktop,” says Medialets COO Richy Glassberg. “In desktop, there’s 15 years of technology which allows anybody to build one ad in Flash, it works everywhere.

“In December, with the billions of ads we serve, we saw 30,000 different devices. You have to make an ad work in every type of environment. The scary thing for the agency is, ‘Did my ad work?’.”

“We’re seeing a rate of change we’ve never seen in the advertising world before. I don’t think anybody’s caught up.”

He was speaking to Beet.TV during the Cannes Lions International Festival of Creativity.   Please find more Beet coverage of Cannes Lions here.