Purpose-Understanding customers is critical for service researchers and practitioners. Today, customers are increasingly active online, and valuable information about their opinions, experiences and behaviors can be retrieved from a variety of online platforms. Online customer information creates new opportunities to design personalized and high-quality service. This paper aims to review how netnography as a method can help service researchers and practitioners to better use such data. Design/methodology/approach-A systematic review and analysis were conducted on 321 netnography studies published in marketing journals between 1997 and 2017. Findings-The systematic review reveals that netnography has been applied in a variety of ways across different marketing fields and topics. Based on the analysis of existing netnography literature, empirical, theoretical and methodological recommendations for future netnographic service research are presented. Research limitations/implications-This paper shows how netnography can offer service researchers unprecedented opportunities to access naturalistic online data about customers and, hence, why it is an important method for future service research. Practical implications-Netnographic research can help service firms with, for example, service innovation, advertising and environmental scanning. This paper provides guidelines for service managers who want to use netnography as a market research tool. Originality/value-Netnography has seen limited use in service research despite many promising applications in this field. This paper is the first to encourage and support service researchers in their use of the method and aims to stimulate interesting future netnographic service research.