What causes conversion?

Demand.

It’s a simple answer and worthy of unpacking. 

You could thank Claude C. Hopkins for the simple answer. Hopkins wrote two books towards the end of his life – Scientific Advertising and My Life In Advertising. He seemed to regret his experiences as an agency president, and left some direct advice on how master marketers should think of their choices.

In his last decade of life, Hopkins marketed his marketing expertise. Instead of continuing to take on all the risk of marketing product on behalf of somebody else (and maybe getting paid if the product sold), he set up a system where products would be pitched to him. If the product was good, he’d take a stake and he’d market it. If it wasn’t good, he didn’t. In a way, he came to understand that he was also a product, a towering giant of marketing worthy of demand.

He was very clear that there was no point in trying to market an inferior product, or to go up against superior alternatives. All the techniques he taught us in the book Scientific Advertising were to prove or disprove the hypothesis that it was a product was worthy of demand. Only great product has the ability to cause great demand. 

A great product alone isn’t enough to cause great demand. Marketing helps people discover and recognize great product. Marketing helps people tell others about that great product. There’s an intersection of art and science that goes into helping people discover great product. Artists work to construct repeatable sentences, divergent creative, and evident value propositions. Scientists work to map and price segments, design experiments, manage bias, and do everything they can to discover and understand the ground truth. The combination of these skills is essential in causing great demand for a great product.
It’s a simple answer.

Demand.