Being one of the “mega trends” that has significantly impacted the tourism system, the role and use of social media in travelers' decision making and in tourism operations and management have been widely discussed in tourism and hospitality research. This study reviews and analyzes all extant social media-related research articles published in academic journals during 2007 to 2011, mainly in tourism and hospitality fields. Based on a content analysis on the analyzed articles from both the consumers' and the suppliers' perspectives, this article found that consumer-centric studies generally focused on the use and impact of social media in the research phase of the travelers' travel planning process. Supplier-related studies have concentrated closely on promotion, management, and research functions, but few discussed product distribution. Research findings thoroughly demonstrate the strategic importance of social media for tourism competitiveness. This study also contributes to the academia and industry by identifying some research voids in extant research and providing an agenda for future research.

Recent press reports and complaints by hoteliers have called into question the credibility of travel-related user-generated content (UGC). Yet our understanding of the role of credibility perceptions in the context of UGC is limited, notwithstanding the rising interest in social media. Using an online survey of 661 travel consumers, this study applies the component-based structural equation modeling technique of partial least squares to examine online travelers’ perceptions of the credibility of UGC sources and how these perceptions influence attitudes and intentions toward UGC utilization in the travel planning process. The model also draws on the theory of homophily to make predictions about the antecedent of credibility. Results validate the Source Credibility Theory in the context of UGC but also accentuate the central mediating role of attitude. In addition, the study finds support for perceptual homophily as a critical determinant of both credibility and attitude. Theoretical and managerial implications are highlighted.