The ka-ching is a generic cash register effect rather than a line from one film or show, built from the bell of a mechanical till and the clink of coins. It became shorthand for money in cartoons, adverts and comedy sketches because listeners instantly understand it without any words. Online, editors reuse the same short clip in memes, TikTok videos and YouTube edits whenever a character earns, spends or wins money. Its brevity and instant recognition keep it useful decades after mechanical registers disappeared from most shops.