Why do we expect toothpaste to tingle? Why is the pop of a Snapple cap so satisfying? And how did a functionless fizzing sensation turn bath bombs into a social media phenomenon? This episode uncovers the surprising psychology behind the "tingle factor"—those completely unnecessary sensory features that somehow become the most important part of a product. From the accidental discovery that revolutionized American dental hygiene to the carefully engineered crunch of a Pringle, discover how the most successful brands hack our brains by creating sensations that serve no purpose except to make us crave more.