All groups of people - small firms, global companies, домохозяйства, countries, nations and international organizations are can be examined as consumers of concrete commodities, services and ideas.A sale, speaking по-научному, - it the process of transmission of commodities and services from hands that, who produces these goods and services, in hands that, who will be able to turn to from their application maximal advantage. A Purchase-sale became world business in complete sense of it words. A sale is attended with the art of persuasion (a selling side must own them).