It is worth mentioning that to have stable and consistent sales, we need to know and act on different ways of communicating with the customer. On the other hand, trust in the manager is difficult in any job. Indeed, no progress is possible due to the lack of trust between the manager and the management staff and the buyers, and so on. Due to the historical view, before the Industrial Revolution, trade and commerce were more relationship-oriented. After the Industrial Revolution, when a large amount of production grew rapidly with new methods and subsequent mass consumption, intermediaries in the distribution chain became more powerful, and the traditional relationship between producers and customers was severed. As a result, distribution spread over a wide geographical area, which demanded mass distribution and marketing. This trend was seen as the supporter of the marketing and advertising clinic - the profitability of many companies - when demand exceeded supply. Moreover, from an exchange marketing perspective, regardless of whether the customer is old or new, marketing and advertising Clinic - marketing programs are designed to facilitate the exchange of products and goods as well. All these factors have been accumulated to raise the issue of exchange more seriously. As a result, all efforts were made to increase the number and quantity of customer purchases, which resulted in little funding to build a stable relationship with older customers. In this case, price became an important issue, and marketers strived to encourage buyers to buy again. 
Regardless of whether each buyer has already made a purchase or not. In this situation, the main competition was to maintain service and product development to the customer and facilitate the customer's purchase, not to maintain existing relationships with existing customers. Due to the customer relationship marketing perspective, the relationship between the parties to the exchange is the core of the marketing phenomenon. In this case, constant purchases and resale opportunities are pursued through proper relationship management.
Customer Relationship Management
Customer relationship management is based on the exchange of value between the customer and the organization and emphasizes the value established in this relationship. Therefore, the organization's efforts to develop long-term relationships with customers, based on establishing value for both parties is one of the main goals of customer relationship management, On the other hand, the goal of customer relationship management is to provide benefits through mutual exchange and the fulfillment of promises. 
Customer relationship management is a business strategy that is strengthened by the advancement of technology and through it, companies establish useful relationships based on optimizing the received and perceived value of customers. Moreover, the term customer relationship management is also closely related to the following concepts:
- Database marketing;
- Single (One-to-one ) marketing;
Benefits of Customer Relationship Management for Customers: The basis of customer relationship management is the value that is provided to the customer and this value is something that the customer has a positive understanding. Furthermore, this value can provide benefits to the customer in the following ways.
Steps of service delivery, customer relationship management
In the first stage of providing customer relationship management service, a database is prepared based on customer information and data. Then, the information collected in the database is analyzed based on various techniques. Target customers are selected based on the company's profitability criteria. In the next step, a suitable marketing combination is designed for the target customers. Then, using the information from the previous steps, customers are contacted, and finally, after the implementation of related marketing, the results are controlled and evaluated.