Recognizing the importance of product reviews for product sales in online retail platforms, this dissertation studies the effect of electronic word-of-mouth (e-WOM) dynamics on consumer behavior, including information processing, review-reading behavior, product evaluation, purchase decision, and reviewing behavior. In the first essay, I focus on incentivized reviews, which are posted by reviewers who received economic incentives (e.g., free product) from the firm, and explore how their emergence in a reviewing system influences subsequent organic (i.e., nonincentivized) review contributions for the focal product. I find that the ratings of subsequent organic reviews decrease after the appearance of incentivized reviews and that the magnitude of this negative impact decreases over time and the ratings recover in the long run. This is because subsequent reviewers adjust their product evaluations downwards when faced with priorincentivized reviews. In the second essay, I study the effect of a prevalence phenomenon— repetition in e-WOM—on consumer behavior. I demonstrate that high repetition in e-WOM could have a negative effect on persuasion and that this negative effect could be eliminated by modifying consumers’ inferences about the cause of repetition. Furthermore, consumers’ information-seeking behaviors are also affected by the share and type of repetition. Both essays provide an understanding of the impact of e-WOM on consumers’ judgments and decisions and offer implications for firms and platforms on how to gather, manage, and display e-WOM effectively; they also provide interesting avenues for future research.