, dahat wrote

So every single marketing and advertising company and department which sells is... wrong?

You are confusing selling with advertising.

Advertising tries to pursuade potential buyers that they want to buy product X instead of Y.

Selling is finding out what product the potential buyer wants to buy, and then sell it to them.

Advertising creates the pull-through that good selling can then capitalise on.

i.e. If advertising has convinced the market they need Micro-SD in their phone, you'll have a tough job trying to sell them one without it.