During the past 18 months, they ordered one, two, or several books on marketing and sales through direct mail ads. Their interest in this field ranges from the broad concepts of marketing strategy down to the specific tactics used to sell any product or service. Most of them play key roles in the formulation of corporate and sales strategies, product conceptualization, price-setting, promotion, and distribution. They are mostly CEOs, Directors for Marketing & Sales, Customer Service Managers, Sales Managers, etc. Others are entrepreneurs or self-employed professionals whose success depends on being able to sell in the domestic or in the international market. Some work for companies in the marketing service industry. There are also those who are not in marketing and sales per se, but who realize that an understanding of this field helps them make good decision in their own areas. Source: mail order houses.