What We Know and Don’t Know About Online Word-Of-Mouth: A Systematic Review and Synthesis of the Literature

Abstract

Online word-of-mouth (eWOM) has attracted considerable research in the past decade. Yet, no attempt has been made to consolidate and synthesize this stream of literature. Based on a systematic review of 148 studies, the authors conduct a multi-dimensional analysis of eWOM communication, consumption and effects. Results show that the factors that drive consumers to generate/transmit eWOM include need for self-enhancement, social interaction and altruism. These factors also assure the generation of quality information that benefits consumers who seek eWOM. The findings indicate that the effects of eWOM on consumer and market-level outcomes are not linear and vary significantly owing to eWOM dimensions such as valence and volume, and across products and consumers. With social media and other eWOM platforms taking central stage in marketing and promotional strategies, it is important to consider the key effects of eWOM on metrics such as consumer loyalty, life-time value and service delivery costs.