The cash register sound is a classic stock effect rather than a clip from one identifiable film or show, built around the familiar noises of an old mechanical till. Because that cha-ching has long signalled a sale in cartoons, comedy sketches and shop scenes, viewers recognise it instantly even in a two-second clip. Online it spread as a shorthand for making money, closing a deal or winning a prize, and creators now drop it into memes, reaction videos and short-form edits whenever a joke needs an instant payoff about cash.