This idea has been credited to Socrates who was famous for asking questions rather than making statements in his dealing with people. This allowed him to understand them in a deeper way.
Unfortunately over the years sales people have been taught this as a “sales technique“ in order to coerce a customer to buy something. Having been associated with the sales industry for most of my adult life, I find the idea of manipulation detestable.
What Socrates and Dale Carnegie meant by this method was, to find areas in which you agree with someone. There will be places where we disagree, but looking for where we agree does a couple of things. It causes us to think in terms of the other person’s interests and it takes our focus off of where we disagree. We are more likely to find common ground where we agree. We are more open to someone else’s views when we feel they understand ours. We feel validated.
“In talking with people, don’t begin by discussing the things On which you differ. Begin by emphasizing – and keep on emphasizing – the things on which you agree. Keep emphasizing – if possible – that you were both striving for the same end and you’re only difference is one of method and not purpose.“
- Dale Carnegie; How To Win Friends and Influence People
So, get the other person saying “yes, yes” immediately, and do it sincerely.