George Maxwell has been a sales rep for GroWell for 18 years. When he began his career with GroWell he followed the money and sold to any customer he could convince to buy. In the last five years, however, he has been focusing on acting with integrity in every selling situation. As a result, he has discovered that his initial close rate on sales has gone down, but that he has developed a highly profitable group of long-term customers. What principle does this most likely demonstrate