Isn't what you're talking about actually what a medical expert in their field should do, rather than a sales and marketing tactic? I mean, when you go to a doctor, they don't have any intention of marketing what you need to you in exchange for money. They are there completely to focus on the problem you're experiencing, figure out what's causing it, and offer you a solution. Plus, if there are different treatment options, you have the right to choose; for a condition you might have, you can choose to refuse medication and ask for physical therapy instead. Refusing treatment is also an option, and in that case, the doctor gets a written consent from you stating that you refuse treatment because their job is to treat you, but they have to present you as the obstacle standing in the way of that.
When do we visit a doctor? When we have a physical or mental problem, and we should not buy a specific medicine or treatment to find a solution to that problem. A doctor's responsibility is to find out the problem and provide the right treatment after finding the problem. And the benefits or risks of the treatment should be easily understood. The patient has the opportunity to make a decision about his condition. Again, even if the patient decides not to seek treatment, it is important to give him a clear idea of the possible consequences.
Just signing a paper does not ensure that the patient understands the matter well. In my opinion, the biggest responsibility of a doctor is to provide the right treatment according to the patient's needs without thinking about his own profit. Only when the patient understands that the doctor is not forcing him to take anything but is helping him to make the right decision, then real trust is created in the doctor. This trust is not earned through any sales tactics, but through good deeds and responsible behavior.