You’ve read all of your free items this month. To register, get added benefits and unlimited access to articles, Become a Member. Already a Member? Sign in. Advertising Age Article Abstract You'll Only See This Magnum Ice-Cream Ad When It's 'Hot' Company Debuts Taxi Ads That Can Only be Seen When Things Heat Up , Published on July 18, 2013 3 Want more Access, Content & Connections? Upgrade to Membership. We are glad you are enjoying Advertising Age. To get uninterrupted access and additional benefits, become a member today. Become a Member Already a member? Log in.