Customer service is an essential element for the success and growth of companies in general. In this context, this study sought to analyze this service as an element of competitive advantage in a retail company in the optical industry. To reach the proposed objective, qualitative research was performed with a single case study and data collection through interviews, observation, and document analysis. The results show that to be a competitive advantage, customer service must be the subject of strategic actions, must use of social networks, be associated with loyalty tools, and be established as an instrument of organizational competitiveness.