If we created a course for a college curriculum, it would be titled:
The Art of Listening and Watching 101
People who try to influence others – to persuade or sell something to them – would be well-advised to stop talking, and start watching and listening.
The person you're trying to persuade will often tell you exactly what he or she is thinking. It's just that we as a society have been trained to talk...but not to listen.
(Consider the fact that body language experts are quite adept at discerning a person's attitudes just by watching his or her positioning and movement.)
Follow this rule when trying to persuade another to your point of view:
Listen carefully to every word he or she says. You may just get a roadmap to how to influence this person's thinking.
Focus with all your might on the other person. What's being said and how? What does this person feel strongly about? What about your product or idea can mesh with this person's hot buttons? Can you modify your proposal to intersect more closely with what this person believes?
The art of a successful sales presentation is not to go on and on about the merits of your product or idea. Instead, you must explain to others why your product or idea will satisfy a need or desire.
But to understand what their needs or desires are, you must learn to be a good listener.
Check out the book The Skinny On The Art Of Persuasion.