CANNES — The ad spend on paid media has dramatically dropped over the decades, representing one of the biggest evolutions in the marketing business, Group M’s Irwin Gotlieb tells Maria Mandel, VP Marketing at AT&T AdWorks, during this leadership session with AT&T AdWorks on “The Dawn of Targeted TV Advertising” at Cannes.

The shift in shelf space from physical space in years gone by to the more e-commerce centric world of today is driving new ways of thinking about paid versus other forms of media. Clients spent 75% of their marketing dollars on paid media 45 years ago and today that number is below 25% with the money going to trade support, he says.

“Media is becoming virtual shelf space,” he says. “If you can activate it or post it on a wish list, or put it in a shopping cart or click and get a coupon — something that makes media a transaction, that changes the definition.”

Gottlieb spoke with Mandel during this leadership session with AT&T AdWorks on “The Dawn of Targeted TV Advertising” at Cannes. The program was sponsored by AT&T and presented with Beet.TV. You can find more videos from the session here.