The marketing mix traditionally uses four variables (4P) on which an individual, a group of individuals, or a company can pass to achieve the objectives of its customers the product, the place (distribution technique), the price and promotion (communication technique). At the beginning of this century, among a number of elements, a fifth (P) is becoming increasingly important. It', s the personality of the clientele. Some authors even insist on that of the entrepreneur. In this article, we present to marketers in general and business enthusiasts in particular, a new approach, that of relationship marketing (the one to one) also called personalized marketing that follows the 4P of operational marketing. This approach consists in individualizing marketing promotion and communication actions according to the expectations and the project of each client or prospect. To each individual must correspond a particular action or offer.