Customer retention is the set of efforts made by a company to retain existing customers and retain them over the long term. This involves putting strategies and programs in place to meet customer needs, solve customer problems, provide benefits and rewards, and maintain regular communication with them. Customer retention is important to a company's growth and profitability because it helps reduce the costs of marketing and acquiring new customers, while increasing the lifetime value of existing customers.
Here is a more detailed article (in french) on the subject : Comment Dsales vous aide à booster votre rétention client ?