> Companies can develop new products without your advice. In fact consumers often don't know what they want.

I'd urge reading up on revealed preference and product discovery. It cuts both ways in that, sure, a company can offer a product on the market that no buyer asked for and have it sell well, but then, the media can expose some rather unsavory facts about that same product and subsequently (consequently?) have it not sell.

> Then why do businesses have sales? If prices don't matter why would businesses choose to make less money per sale?

It's worth picking this apart. Prices not mattering is usually expressed in economics-ese as price-inelastic demand, and that's usually not what's happening. Sales are a mechanism for drumming up demand for a product, with the hope that the additional volume will compensate for the marginally lower margin.