The ethical questions we deal with in advertising and marketing are certainly not new. Ask St. Thomas Aquinas.
He addressed the topic of "Cheating Which Is Committed in Buying and Selling." He answered such questions as "whether it is lawful to sell a thing for more than its worth", and "whether the seller is bound to state the defects of the things sold". He even dealt with "whether in trading it is lawful to sell a thing at a higher price than what was paid for it". He must have known the guy who sold me my last car.
Today we frame those kinds of questions differently. Usually they're not even questions --- they're insults.
"Advertising makes people buy things they don't need!" Of course we do. We already have food and a place to live and enough clothes to never have to go to H&M again. But what's wrong with simply wanting something? Anyway, if we in advertising had the power to make you buy it, we'd be millionaires many times over.
"Because of marketing, the price of some things is twice what it costs to make them!" That's true, too. Some products wouldn't sell without promotion because how would you know they exist and why they're good? Who would pay the stores and salespeople? Without advertising, only a small quantity would be sold, and economies of scale would be lost.
"Some products that are advertised sell for a lot more than they're worth!" Who's deciding what they're worth? Be sure to measure the confident, independent feeling a woman gets when she puts on Chanel No. 5. Or the winning feeling when a guy puts on his Nikes and gets in the game. The market decides on worth, not you or me.
Now to the seller's responsibility to disclose what's wrong with a product. Essentially I agree it is her responsibility. "Batteries not included" for instance, or "Not intended to cure any disease". Those seem okay to me, but I'm not sure the ad has to tell you that some people don't like the taste or that we used some artificial flavoring. The buyer has some responsibility, too. Such as not letting their kids eat too many fries, or reading a package.
Today we don't expect a store to sell something for just what they paid for it. We know that profit is a good thing. It pays our employees, our rent, and enables the owners to get paid for their risks and to improve things.
But it's also crucial that we don't overlook ethics in our work as professionals. We know what's right and wrong, and we also know our futures depend on it.