When you talk to different people, they will tell you a very different selling skills, some could be manipulative, some are aggressive, and some could just be like a causal conversation. But I can tell you, there is no perfect way to persuade people, because we are all behave very differently. However, to know how to sell, all you need is to understand who are you persuading to, and use the right skills to accomplish your goal. Hence I use economics with persuasion, which allows me to first understand your market, and then use the right technique on the right people.
If you are talking about a market, every persuasion skills you use will have an effect on the market, because if you sell a product below the market price, you could trigger a price war with your competitors, therefore if you do not understand the behaviour of your existing market, and start messing around with it, you could have done more damage than good.