Why do we trust in online reviews? Integrative literature review and future research directions

Online reviews are an important information source in decision-making processes. Basing decisions on online reviews, however, requires consumers to trust. Consequently, studying trust has become a major research concern. This article provides an integrative literature review of 70 articles published between 2005 and 2021 that, using both quantitative and qualitative approaches, investigated which factors affect trust in the context of online reviews. Results show that research examined 77 different factors for their effect on trust. For most factors—such as integrity of reviewer, quality of argument, and consistency of review with other reviews—, the findings are relatively distinct. The impact of some other factors—such as homophily, two-sidedness of reviews, and emotionality of reviews—is less clear. To synthesize and systematize the results, I develop a conceptual framework based on a model of the online review process. This framework identifies six groups of factors, namely factors related to reviewers, opinion seekers, platforms, communities, option providers, and external actors. On a more general level, the review finds that research uses many different operationalizations of trust, yet rarely embraces more comprehensive concepts of trust. Based on an assessment of the state of the field, I suggest that future research should corroborate, integrate, and expand upon this body of knowledge.