This final paper deals with the thematic area of personality types of people and it's character and temperament. The meaning of the concept of introversion, extroversion and diversity of individuals in view of decision-making priorities, does the individual rely on intellect or emotion when decisions are made. There are different types of personalities which are divided in this final paper and their basic characteristics are explained to extroverted persons guided by intellect on the one hand or emotions on the other, and introverted individuals guided by intellect or those guided by emotions. Based on the explanation of personality types, a link is generally added to the types of customers who, when making purchasing decisions and generally behavior, are guided by their type of personality. The principles from the seller's perspective are in detail presented according to which he accesses each of the detailed types of buyers, which are called synonyms red, yellow, blue and green. In the empirical part of this paper, observations of a personal observation of the relationship between sellers and different types of customers are presented. After observing the seller M. B. the author of this paper has come to the conclusion that the study of customer personality types can greatly facilitate the sales process and maximize customer satisfaction. A salesman who approaches each of the different types of customers differently and, considering the knowledge from the literature, validates these claims in practice. The objective of this paper is to provide readers with a systematic overview of the access rules for each type of customer in order to achieve greater sales efficiency.