Although it would be a world very different from ours, I wonder what the consequences of an ad-ban would be? You create a business or service, but the only way

Although it would be a world very different from ours, I wonder what the consequences of an ad-ban would be? You create a business or service, but the only way an individual could discover it is by intentionally going out and seeking that information (perhaps you've made a new washing machine, and they seek out information for washing machines). Perhaps specialised 'discovery' services would pop up for people wondering what sorts of new stuff/services was out there? On the surface of it, I'd assume that if reaching out to customers to 'let them know you exist' via advertisements was prohibited, the amount of innovation and investment into products would decrease. But at the same time, the amount of money allocatable to product development within a given budget would increase, as you wouldn't have to expend so much on marketing (which in some cases, dwarfs the cost of R&D). But maybe the markets would just adapt anyways. Seems a fun thought experiment.