Many companies carry out the same activities, offer similar products and services but each company seeks to satisfy and retain its customers so that it can increase its profitability, so it is because of competitive pressure that companies are looking to further increase their customer base. Hence to guarantee more advantages in the market over the competitor, companies are obliged to serve their customers in the best way possible: we are talking about the customer relationship. What is a customer relationship? First of all, it is a fundamental marketing concept. We can therefore say 'Relationship marketing' which represents a set of marketing actions and strategies to improve and guarantee a lasting relationship with customers. A customer relationship or customer relationship is a concept that includes all management tasks applied to interactions with the customer. This relationship is at the centre of every company's activity, it is important enough for companies to emphasize the quality of their customer service as an added value. So a well optimized and efficient customer relationship is a major factor for the economic growth of companies. It is a very strong marketing skill. How can this relationship be optimised? Good customer relationship management requires an effort from all entrepreneurs and their teams. It is necessary to give all the attention to all the tasks of the mission whether it is pre-sales prospecting or after-sales service. Nowadays customers demand and expect more authenticity from brands. For this reason, personal marketing focuses on customer relations to strengthen it and with the help of social networks that companies can have a bond of commitment on the part of consumers. These consumers are required to share their opinions, whether positive or negative. This is a great opportunity to better understand its targets and identify the damage to overcome and change them. These social channels are different and difficult to manage, but are gradually becoming more and more important, hence the use of CRM seems to be one of the solutions. But what is a CRM? CRM:Customer Relationship Management It is a software, a computer tool that allows to manage customer relations. This software takes into account the interactions and the engagement of the consumers. It allows the creation of data entry sheets and modules, it even allows to archive all the useful and necessary data about a customer portfolio. Its data allows the personalization of communications with customers in order to provide them with a particular service that builds loyalty. Moreover, it allows companies to show its ability to listen to all the expectations of all customers. The more complete the CRM is and includes all the necessary data, the more efficiently and satisfactorily the company uses it to achieve economic growth and increase profitability. The importance of the quality of customer relations cannot be denied: This relationship evolves in parallel with the company's mission, whatever the sales of goods, finished products or services, the dissatisfaction of a customer has a negative impact on the company. Thanks to the CRM, the company can manage and settle all conflicts on this basis of tangible information. The use of very detailed approaches is necessary to have a good quality customer relationship, such as the creation of interactions always more human seems the most important, a key to customer satisfaction as we have already seen it is through social channels but this quality is not only evaluated by the channels but also by all the contacts that the customer will really act. So you have to be accessible everywhere and all the time. The company must adapt to the new uses of its customers which is to say it must be ubiquitous in all channels since consumers always expect brands to be on different channels while benefiting from an experience both relevant and consistent on each of them and especially equipped with devices always connected because it is necessary to react quickly to consumer feedback using CRM software. So to really optimize customer relations, it is necessary to react to all complaints in a positive and honest manner while taking responsibility for immediately resolving the problems facing the company and communicating with customers about the company's actions. These crucial steps can turn an annoyed customer into a loyal ambassador for a company's brand. Last but not least, all companies need to anticipate customer needs and expectations. This means observing trends, identifying and analyzing behaviors to better understand and predict future actions. Therefore, companies must have a permanent tool that serves to better know their customers, which ultimately leads to developing the level of product or service sales, but it must be through channels that are best adapted by consumers. For a company to be competitively successful, it must manage its customer relationships well. This is essential. For all companies, the customer represents a potential turnover, so it is necessary to have the necessary attention. The company has to be reactive and communicative by responding to customer needs and offering the right service or product at the best price.