I agree with the point made earlier that manipulation and persuasion have some relation to each other, though manipulation tends to have a worse reputation that persuasion. Perhaps the differentiating factor though is the degree to which the recipient is aware that they are changing their mind. With persuasion (more presentation of facts and leaving more thought for the recipient to form their own opinion), the one on the receiving end has a good deal of conscious control of the formation of their opinion about something. In this one can often pinpoint why they feel a certain way or take a certain stance about a product. But in manipulation as it is commonly understood, the recipient does not always realize that they are subconsciously making an opinion about something in the first place, much less even being able to pinpoint the specific reasons they feel a certain way. Some tactics that manipulation often leverages are emotional triggers, subliminal messaging, as well as other, less direct methods of conveying a message (music, colors, etc.) Fortunately or unfortunately, the more common form of the two that manifests is manipulation (though it is more tame than the reputation around the term insinuates), which can be seen in almost every advertisement available today. From the music choice, to the people representing the product, though the ad explicitly says one message, a whole barrage of implicit forces are being employed in order to reinforce that explicit message, or even convey a new message altogether.