"Mass" advertising and Madison Avenue, yes, but their were also many things you'd consider advertising - the first newspapers all had ads. Even before that the

"Mass" advertising and Madison Avenue, yes, but their were also many things you'd consider advertising - the first newspapers all had ads. Even before that the typical industrial revolution town square had tons of advertising. Before that it was actual street hawkers. Advertising is just business owners saying "My product exists, look at it, you might find it useful!". Without it, product discovery has to be be a top down directory which means relying on someone's judgement instead of the market, which has basically been shown to be inferior at scale everywhere it's been tried.