If there was any doubt that everything is an ad network, this year’s Cannes Lions Festival of Creativity proves otherwise. To Peggy McCann, chief media officer at GSD&M ad agency, all signs point to one thing: retail media networks aren’t going anywhere anytime soon. It’s a tall order, but perhaps fits within the expectations of Cannes’ pageantry. For media planners like McCann, the question is: is the Cannes flash enough to attract ad spend?