The cha-ching of a cash register has been shorthand for money in cartoons, adverts and comedy for decades, long before short soundboard clips existed. As mechanical tills disappeared, the recorded ring stayed as a cultural cue for a sale, a profit or getting paid. This short cash version spread in edit culture because it says all of that in seconds without context, so creators reuse it for finance jokes, business wins, shopping videos and ironic flexes where the amount is tiny but the reaction is made to feel huge.