He has grasped that profound truism that customers don't care how much salespeople know until they know how much salespeople care. Note, it's not that customers don't care how much salespeople know. They certainly do care, as John F. Lawhon rightly insists. It's simply that customers do not appear to care until they know how much their salesperson cares. Through the law of reciprocity, the philosophy of win-win takes customer and salesperson to where both can have the things they want and at a higher level than if each of them were to go it alone.
Salespeople can do all that by lending a sense of logic to their customers' emotions.
By doing that, they can learn to handle their customers' emotions ethically. Corporate trainer, educator and speaker Dr. Peter A. Marino has written extensively on sales training techniques and their furniture retailing applications.