Meghan called. She was a high school senior, my daughter's friend and classmate. She had a summer job selling for a cutlery company, and wanted to "practice" her presentation in front of us in our home. We said sure.

On the appointed evening, Meghan lugged her sales case through the front door and opened it on the dining-room table. While unpacking, she asked me to get her a glass of water. I did, and then she asked me to bring her the knives we currently used.

I went back to the kitchen and returned with the knives.

"So, how would you describe your current knives?" she asked.

"Old, dull, and inadequate," I said.

"Why do you say that?"

I told her that I inherited most of my knives from my grandfather, and I'd bought one in a hardware store on 9th Avenue in New York City.

She pulled a 9-inch length of rope from her case, and asked me to cut it with my sharpest knife.

"My sharpest? That's not saying much," I said. I picked up my grandfather's carving knife, which has a deer antler as a handle.

Meghan held the rope down on a cutting board that she had pulled from her bag. "Count the movements back and forth," she said.

I began to saw. It took 14 movements.

"Now hold the rope down for me," she said, grabbing one of her knives. "And count the saws it takes me with this knife."

It took her four.

"Let me try that," I said. I took the knife from her and she held the rope down. I sawed through the rope in two strokes. It was like cutting warm butter.

Meghan asked me to bring my best pair of kitchen scissors to the table. They could not even slice a strand of the rope. I took hold of her scissors and not only cut through the rope with ease, I also cut a penny in half.

Sold. She gave me information about the steel and the handles, but I barely heard her. We ended up, or rather my wife Sharon ended up, buying all of the kitchen knives and a set of 12 steak knives. Eleven years later, the knives are still in the kitchen, and Meghan will be Dr. O'Brien on May 18th.

So, what are the 10 principles of persuasion that made the pitch so successful?

Here they are, in no particular order:

The Experiment Principle

Meghan positioned the presentation as an experiment--a game--and a chance for her to practice her presentation, which removed the pressure and put us in the role of mentors, not buyers.

If you're in business, you can do this when you have a new idea that's meeting resistance. Call your idea an experiment and your bosses will be more likely to say, "All right, go ahead and try."

The Agora Principle

Agora is the Greek word for marketplace. In Meghan's case, the marketplace was our home, so some part of our brains saw her not as a peddler to be distrusted but as a guest, someone to be treated well.

Get your prospect in the right setting and they're more likely to say yes.

The Principle of Contrast

With her rope and penny tricks, Meghan created a vivid contrast between our knives and her knives. In other words, she created tension between the As-Is state and the Could-Be state. In my mind, I saw the dark, dull past dissolve and the bright, new future emerging.

This is crucial. In almost all sales situations, you need to define the problem and paint the picture of the future state.

Know-the-Audience Principle

Meghan knew our family well. We trusted her, she trusted us, we were friends with her parents. In fact, we were part of the village that was raising the child. The exchange in our dining room personified the saying, "It's not what you know, it's who you know."

Since everyone has clients and prospects, you need to build relationships by finding common ground, and do such good work that your clients (and maybe even your prospects) feel comfortable referring you to others.

The Principle of Simplicity/Clarity

Meghan's message was not complicated, detailed, data-driven, or delivered in unfamiliar words and phrases. There were no charts, graphs, or PowerPoints. We didn't need big data to find the signal within the noise. It was clear to the eye and the hand: Our knives were old, dull, and inadequate. Meghan's were new, sharp, and reliable.

In sales, using your own jargon and speaking in a high-falutin' way is a dead end. Lose the jargon and the fat words.

The Principle of Specificity

Specifics are more persuasive than generalities. Meghan's knives were not just newer and generally better than our old ones, they were quantifiably better, specifically better. With my grandfather's knife, I took 14 backs-and-forths to cut the rope, compared to only two with Meghan's knife. Her knives were seven times sharper and more efficient than mine.

If you bought a copy machine for the office that was seven times more efficient than the old one, everyone would say, "Dude!!!!"

The Similarity Principle

We're more likely to trust and do business with people who are similar to us. Meghan's company took advantage of this truth: they hired high school kids to call on their parents' friends. Talk about the sales path of least resistance.

Despite the vast changes wrought by the Internet, at the heart of sales is a conversation between two people. At some point, for a transaction to occur, a spark of confidence must leap from seller to buyer. It happens more often between people of similar backgrounds.

Active vs. Passive Audience

An active audience is more easily persuaded than one that's passive. Meghan had me bring her water and knives. She had me cut the rope with my own knife, and then with one of hers. She asked me questions, listened, and then asked follow-up questions. My God! I even cut a penny in half with a pair of scissors! I was deeply involved.

In this day and age, when even our cars talk to us, getting your prospects to talk is a critical necessity. At the very least, plan for Q&A. And shoot for talking 20 percent of the time, listening 80 percent.

The Principle of Conformity

People are persuaded in response to real or imagined group pressure. Being socially correct yields approval and avoids disapproval. We knew that other families in town had bought knives from Meghan, and we wanted to be seen as supportive of her. We knew she would tell her parents that we had bought knives, and we valued their friendship.

In other words, most people tend to go along to get along. When in Rome.... Hey, nobody ever got fired for hiring IBM.

The Principle of Commitment or Consistency

People feel pressure to honor and to behave consistently with their prior commitments. Sharon and I were committed to raising our daughter with our values. We extended that commitment to her friends. The act of buying knives from Meghan reinforced our commitment to our own values--to be encouraging and supportive of young people. It made us feel good about ourselves.

If you can link your persuasive appeals to the visions, missions, and values of your prospects, whether they're individuals or companies, you have a better chance of getting to yes.