The growth of social media has profoundly changed the way companies and consumers interact. Communication that used to be unidirectional, from company to consumer, has become fully interactive both between consumers and between consumers and companies (Farquhar and Rowley, 2006; Fisk et al., 2008; Hanna et al., 2011). Consumers now use the Web to express their knowledge and experience of products and services, and word-of-mouth has become a significant component of online consumer interactions (Valck et al., 2009; Brown, 2006; Brown et al., 2007). The vast amount of information shared by consumers within the scope of social media allows companies to better understand and respond to their needs. At the same time, the emergence of social media enables the creation of many new points of contact between companies and their customers, as well as new opportunities for value co-creation (Prahalad and Ramaswamy, 2004). Besides the collection of relevant consumer data, consumer engagement in social media can be used by companies to reach new potential customers, to facilitate unique experiences that increase consumer affective connection, to improve customer service and even to foster collective innovation (Kao et al., 2016). Among social media, social networking sites (SNSs) have become an important channel for companies to both communicate with consumers and foster interactions among them. Many companies have created their own consumer social networks around their pages, hereafter referred to as company social networks (CSNs), in the most populated SNSs, such as Facebook, Twitter, YouTube, Instagram or Pinterest. In 2016, Facebook had about 60 million business pages (Business Insider, 2016). Membership and participation in these CSNs have become important components of the overall customer experience (Verhoef et al., 2009). However, in spite of the growing importance of the CSN phenomenon, managing the presence in SNSs remains a challenge for most organizations. First, some companies hosting pages in SNS have been unable to attract enough consumers to create a relevant social network. Many others have formed social networks, but have been incapable of energizing them. A 2012 study showed that more than 70 per cent of business pages on Facebook were completely inactive (Digital Strategy Consulting, 2012), demonstrating that engaging members is not a straightforward task. Thus, to attract and engage consumers, companies need to understand how they can promote loyalty to their CSNs. Some studies have already examined CSNs, addressing them as online brand communities (Azar et al., 2016; Jahn and Kunz, 2012; Kang et al., 2014). However, their results suggest that besides communities, CSNs may also be viewed as services. In light of service literature, CSNs present characteristics of supplementary services through which companies facilitate the use and enhance their core offerings (Lovelock, 1995). Among such research, Jahn and Kunz (2012) found that functional value explains Facebook page usage intensity significantly better than hedonic and social value. Martins and Patrício (2013) found that the content of CSNs tends to be mostly created by the host, and that host–consumer interactions are more frequent than interactions between consumers. As such, research on loyalty toward CSNs could benefit from considering service research concepts and methods. Taking these challenges into account, this study builds upon service quality approaches to identify, understand and measure CSN dimensions that can foster CSN loyalty.