In the 1920s, Schlitz beer went from 5th in the market to a tie for first. All because a sharp copywriter named Claude Hopkins highlighted their water purification process in an advertisement.
Never mind that all beer companies used the same process. No one had told that story before.
Advertisers became more astute after that point, which led to the development of the unique selling proposition by a guy named Rosser Reeves. This was the beneficial feature of a product or service that the competition would not, or could not offer.