Comment by bee_rider

Some of the demand induced by ads is useful; people becoming aware of stuff they didn’t know exists, and finding that it provides a useful service for them.

But most ads are trying to convince you to buy their brand’s version of a product that you already know of, or (even worse!) a new version of an old product. Any demand induced there is just wastefulness.

If Amazon can figure out that I’m interested in headphones, I already know more actual information about headphones than their ads will give me.