When Burger King tasked MullenLowe, with coming up with a "killer idea," the agency looked to the past and found Funnel Cake Fries, which debuted 10 years ago and had fallen off the menu. 

Then it began liking old tweets of social influencers, leading one, vlogger Casey Neistat, to pick a beef as it were with the fast food giant. He posted a long video on YouTube, arguing that he and others had been used to sell "sugar coated French fries." But, he went on, the thing that upset him the most? "How genius it was! We were like the little mice—we went for the cheese in the trap and it snapped on us! You win, Burger King!”

Diego Suarez, Lead, US Media, Advertising and Communications, Burger King, on Thursday showed the video as a way of explaining how the brand is always trying to get "share of mouth." 

"We got two videos out of [the prank]," he said. "We were able to introduce [Funnel Cake Fries] to a younger generation that is addicted to social media and to Casey Neistat."