Unlike Vayner, Shell and Moussa possess plenty of credibility in the eyes of this audience and in those of the businesspeople to whom they travel to consult—a week earlier, Shell was dodging engineers on scooters at Google’s headquarters. He’s traveled to Davos to speak at the World Economic Forum and around the country and the world to consult for firms including Morgan Stanley, Citibank, Merck, General Electric, and Johnson & Johnson. Moussa, a principal at the Center for Applied Research (CFAR), a Philadelphia-based management-consulting firm that began life as a Wharton research center, works regularly with pharmaceutical firms and hospitals on forging better collaborative relationships between the commercial side and the scientists. Plus, there’s that book they spent three years researching and writing. It came out last fall and already an audio version is in the works; and the book is available in Chinese, Portuguese, and in the UK.

As Shell and Moussa recount during the persuasion workshop, both noticed that the participants in their respective negotiation classes wanted to talk about problems these executives were having with internal negotiations.* “People today are working more across unit boundaries, across offices,” Moussa explains. “And every unit has its own culture, its own way of speaking, its own way of behaving, its own distinctive beliefs. These are differences that aren’t immediately obvious. You might not see them because you are working for the same company, and your mind-set is usually that you are on the same team.”

Even the most trivial decisions in a company, Shell and Moussa say, often involve at least eight people. Larger decisions can involve up to 20. The two show what a manufacturing company’s organizational chart is supposed to look like, with the senior vice president at the top and three department managers directly beneath. The managers report to the senior vice president, and each manager has two or more employees who report to him or her.

Then they juxtapose this orderly chart with one that shows the real power dynamics at play at this mock manufacturing company. This is no tidy family tree. There are large clusters of employees around a few people who are not at the top of the hierarchy but who are clearly the kingmakers. A huge ladder runs up one side of the chart, and somewhere in the middle of the jumble, one pour soul floats to the bottom, his fall softened by a parachute.

In such a fluid corporate culture, “because I said so” and “or else” are not effective strategies. The Art of Woo offers a four-step method that focuses on persuasion via relationship-building rather than force and authoritarianism. The first step is to assess yourself and the person or people you seek to persuade. Then strategize to break through a list of possible barriers that might include your own lack of credibility or perhaps the outdated belief-system of a traditionally minded organization. Third, figure out how to pitch your idea in the most compelling way—that is, one that will move the listener. And finally, close the deal by securing commitments.

“People persuade themselves,” says Moussa. “So, you can try to bulldoze someone and you may be successful in getting them to say yes, but that is a yes that probably will not stick. What sticks is, as we put it, removing the barriers to being heard and, once you have done that, having a good give-and-take discussion. That takes time.”

*The original version of this article incorrectly stated that Mario Moussa had taught in the Wharton School’s Executive Negotiation Workshop and implied that he was co-director with Richard Shell. In fact, Stuart Diamond, Practice Professor of Legal Studies and Business Ethics, is co-director of this program.