In the ultra-competitive world of fast food, Burger King in Brazil found an ideal way of attacking its rivals: by asking customers to set fire to their ads. Fortunately, the arson attacks did not take place in the real world. Thanks to the agency David, augmented reality and the Burger King app, customers could “burn” outdoor ads from rival brands. When the smoke cleared, it revealed a free Whopper that they could claim at their nearest restaurant. It was the hottest thing on social media since Tinder – no matches required.