You might have too narrow a conception of what advertising tries to do. It doesn't necessarily try to induce demand. Instead, it tries to direct demand towards a certain direction.
Everyone knows what Coca-Cola is. But Coke still heavily advertises worldwide. It's not to make people thirsty when they see the ad. It's to make thirsty people think "Huh, a Coke would be quite nice right now" when they're at the store.
Everyone knows what Coca-Cola is. But Coke still heavily advertises worldwide. It's not to make people thirsty when they see the ad. It's to make thirsty people think "Huh, a Coke would be quite nice right now" when they're at the store.