One of the comments, I thought, was pretty interesting. She said,
“A lot of people want to believe that marketing IS manipulation. And maybe the advertising/image side of marketing is a bit manipulative to varying degrees depending on the company and the ethics of those making the image decisions. But marketing isn't just about making a promise, it's about DELIVERING on the promise."
I would tend to agree with that. But I would go further. Marketing isn't (negative) manipulation. It can only be used to manipulate. It's like a knife. It can be used to cut food, or cut people. Marketing is a process of appeal to a market. We can persuade using text, speeches, argument, visuals, and so forth. But manipulation—in the negative sense—is using influence to induce bad choices.
The question, however, is who gets to say what is bad. It seems to me that the absence of this discussion, when discussing ethics, is like talking about choosing flavors of ice cream. It is arbitrary. I might feel good about myself when I only work with clients who promote animal welfare. Though I may feel good about myself, it matters little if they euthanize thousands of animals. Sincerity is not the test for truth.