In this paper, great importance is attached to social networks as tools for the promotion of products and services. Social media has evolved over the last decade and has become an important driver of information acquisition and dissemination in a variety of domains such as business, entertainment, crisis management, and politics. Social media is a phenomenon that has become an important aspect in marketing and a revolutionary way for companies to communicate with customers. Understanding user behavior and characteristics on social media can be a key competitive advantage. When social networks are used properly for marketing, companies can significantly improve their brand awareness, customer satisfaction, quality, reach, and profit. Social media market research is the process of collecting quantitative and / or qualitative data from social media platforms in order to understand social, consumer or market trends. The paper analyzes the origin and evolution of social networks, the characteristics of social network users and provides an insight into marketing on social networks. The application of social networks in researching consumer behavior is investigated. The purpose of this thesis is to define the concept of marketing on social networks, the application of social networks in researching consumer behavior. The aim of this paper is to present the application of social networks in researching consumer behavior.