Well, it could be a number of things, but almost certainly part of the secret lies in the actual words they choose. We are products of our environment. As such, one thing is absolutely certain - we rely upon our five senses to absorb info and learn. And the secret lies right there.
Some people rely most heavily on sight for inputting info. Others may rely most heavily on hearing (perhaps their eyesight is weak). Still others may depend heavily upon touch, smell, or taste. The point is, we are most easily swayed by our dominant sense. If you are sight oriented, you are more apt to believe what you see. If hearing oriented, you may place more importance on what you hear.
That brings us to one of the great secrets of effective communication. If you take a few moments making "small talk" with someone (as good salesmen do), take care to learn which sense seems to be dominant, based on their choice of words. For example, if the person uses phrases like, "I think that stinks", that may hint that smell is one of his more dominant senses. If you hear phrases like, "It sounds good" (hearing), or "It looks good"(sight), you have a clue as to how they absorb input.
Once you know how they assimilate information, you can use that sense to get them to listen to you more intently, and to better understand what you are saying. This can be very persuasive.
In my 35+ year career as a real estate investor, selling homes is often a priority. If I find that the buyer uses "sight" words, then I use sight-oriented info to help him buy. I highlight the beautiful view, for example. If he is hearing oriented, I might mention the sounds of the songbirds, rippling brook, etc. In this fashion, I am better able to capture his attention, and in doing so, persuade him to buy. If he uses a lot of "smell" words, I make sure there are cookies baking in the oven, or lots of flowers.
We all think, learn and communicate according to how we rely upon our senses for data input. You can use that to influence others. The more we rely upon a certain sense for absorbing information into our subconscious mind, the more importance we place on the language that calls that sense into play.
Whether you are selling real estate, or just trying to persuade your teen that smoking is bad, try connecting by using words and phrases the other person is most likely to relate to. In doing so, your power of persuasion can guide you to greater success in all aspects of your life.