Systematic Review: The Role of Electronic Word of Mouth (eWOM) in Shaping Purchasing Decisions in the Digital Era

Abstract

Electronic Word of Mouth (eWOM) has become one of the key factors in consumers' purchase decision-making processes in the digital era. Various empirical studies report the influence of eWOM on purchase intention, brand image formation, and perceived product quality, but the findings and mechanisms of these influences remain varied. This systematic review aims to summarize, synthesize, and evaluate the empirical evidence regarding the effect of eWOM on consumers' purchase decisions based on six attached journal articles. The search and selection of studies were conducted on the submitted set of articles (6 studies). Each article was extracted for the main variables (eWOM, purchase intention, purchase decision), mediation/moderation variables (consumer trust, brand image, perceived quality), research methods, sample, and key findings. Synthesis was carried out narratively and comparatively given the heterogeneity of methods and effect sizes. Analysis of the six studies shows a consistent positive effect of eWOM on purchase intentions and purchase decisions. The most frequently reported mediating factors were consumer trust and brand image, while perceived quality also contributed significantly in several studies. Heterogeneity was found in sample sizes, product contexts (cosmetics, hijab, automotive, organic products), and measurement instruments, which limits quantitative generalization. Several studies recommend the role of social media platforms and eWOM message characteristics (valence, credibility, volume) as strong determinants of the effect. eWOM has a positive and relevant impact on consumers' purchase decisions, with mechanisms often mediated by trust and brand image. For marketing practice, businesses should focus their strategies on enhancing the credibility of eWOM and managing brand image. For future research, a quantitative meta-analysis is recommended if more homogeneous studies become available, as well as cross-product-context and cross-cultural studies.