Online shoppers are increasingly relying on electronic word-of-mouth (eWOM), which refers to Internet-mediated opinions and recommendations on products and services from experienced consumers, to optimize their purchase decisions and reduce purchase risks. Anchored on the theories of message order effects and information chunking, this research investigates how consumers would process and respond to a large volume of review information provided by a eWOM system. The results from a laboratory experiment revealed that when consumers are interacting with online product reviews chunked by valence, the presentation order can influence their product attitude. More specifically, people high in need for cognition showed a pattern primacy effect while those low in need for cognition a pattern of recency effect. In addition, chunking reviews by valence can also benefit eWOM readers' short-term memory so that they can recall more product attribute information mentioned in the reviews, in particular, the product attributes covered by the positive reviews. The implications of these findings for practitioners are also discussed.