Companies use many tricks to convince you to buy things. It might be a glamour shot of a juicy cheeseburger. Or maybe it’s a celebrity praising the usefulness of their products. Believe it or not, there is science behind getting you to buy.

But perhaps the most powerful tool isn’t expensive commercials or celebrity endorsements. Maybe it’s a simple sound. Marketing guru Martin Lindstorm explains how sound triggers the urge to buy. You’ll never listen to commercials the same again.