At one point you’ve probably been that shopper that goes into a store and asks for directions to another store. Usually it’s harmless behaviour. Burger King decided to troll McDonalds by making an offer of a Whopper for a penny, but only if ordered through an app while you’re at McDonalds. Thousands of people flocked to McDonalds restaurants only to order Burger King and ask the staff for directions.

The campaign generated 50,000 Twitter mentions, 3.3 billion impressions, and made the Burger King app number one on both Android and iOS, with 1.5 million downloads in nine days.