What you are already seeing is that advertising is baked into the product instead. I.e. the actual features, functionality or problem solved are themselves finding their ways to the right users.

It used to be that the advertisers used their control over the primarily one way distribution channels to promote their products.

Today it's the consumers who promote the products through the multiway channels and then only if you have exhausted most of your organic, social and viral growth channels do you promote through one-way channels again.