In the conditions of modern digital transformation, social networks are becoming the most important tools for interacting with the audience, forming a brand image and increasing sales. The peculiarities of marketing in social networks are analyzed, the key strategies of attracting and retaining clients for business are argued. The most effective methods of marketing in social networks are substantiated, such as targeted advertising, the use of influential personalities (influencers), the creation of quality content and interaction with clients through direct messages and comments. Different platforms such as Facebook, Instagram, Twitter and LinkedIn are classified, with an emphasis on their features and effectiveness for different types of business. Attention to customer retention strategies, including a personalized approach, creating loyalty through loyalty programs, as well as the use of analytical tools to assess the needs and behavior of users is argued. Presented and structured examples of successful cases of companies using social networks to actively attract and retain clients. The main results of the research are aimed at developing a comprehensive understanding of the features of marketing in social networks, as well as approaches that will help companies to effectively interact with customers, improve their experience and create long-term relationships.