Geoff Burch is a sales trainer in England. He tells about a man named Fred he met in the course of his research into sales methods. Back in the 1950s Fred had been a traveling salesman hawking washing machines. This job was on commission only, but included a valuable and unusual perk: the then almost unheard of luxury of a vehicle. At the beginning of each week Fred was sent off in his van with five washing machines; so long as all five were sold each week, Fred could keep the van. This he succeeded in doing, week after week. It was a matter of honor, he told Burch, that if one of the washers was taken from the van for a demonstration, it was never put back.

Eventually a week came when Fred’s magic seemed to have abandoned him, and to his horror he found on Thursday evening that he had th…