A billion bottles of Coke are sold every day, but did you know they use clever mind tricks to make you want to buy? Back in 1971, Coca-Cola was having a tough time because Pepsi was taking away sales. But then, Coca-Cola came up with a viral idea! They made a jingle, a fun catchy little song that helps people remember their drink. The aim of a jingle is to become an earworm. This is a song that gets stuck in your head and keeps playing over and over again, even when you don't want it to. So Coca-Cola made a special ad called the Hilltop “I’d like to buy the world a Coke” commercial. People around the world loved this ad. It featured people that look like them. The happy and fun ad increased sales. Today, Coca-Cola sells its drinks in 200 countries and makes around forty billion dollars yearly so that