The current state of knowledge on electronic word-of-mouth in advertising research

With the development of new and digital media, consumers are increasingly giving, seeking, and sharing their brand-related experiences via online channels that lead to electronic word-of-mouth (eWOM) communication. Undoubtedly, eWOM has a powerful impact on advertising decisions, and the practice of eWOM advertising has received much attention from advertisers, policy-makers, and the academic community. It is clear as well that, eWOM is believed to influence and shape the future of advertising. Therefore, the purpose of this article is threefold. First, this article provides an overview on the current state of eWOM research, with a focus on how this research has evolved in the advertising literature. Second, we identify and characterize four important trends in the eWOM advertising literature: eWOM and viral advertising, effects of eWOM, drivers of eWOM, and new technologies and eWOM platforms. Third, we develop a research agenda by providing directions for future research as well as implications for advertisers and policy-makers.