Online Social Interactions: A Natural Experiment on Word of Mouth versus Observational Learning

Consumers’ purchase decisions can be influenced by others’ opinions, i.e., word-of-mouth (WOM), and/or others’ actions, i.e., observational learning. While information technologies are creating increasing opportunities for firms to facilitate/manage these two types of social interaction, researchers so far have encountered difficulty in disentangling their competing effects and have provided limited insights into how these two social influences may differ from and interact with each other. Based on a unique natural experimental setting resulting from information policy shifts at the online seller Amazon.com, we design three longitudinal, quasi-experimental field studies to examine three issues regarding the two types of social interaction: (1) their differential impact on product sales, (2) their lifetime effects, and (3) their interaction effects. An intriguing finding is that, while negative WOM is more influential than positive WOM, positive observational learning information significantly increases sales but negative observational learning information has no effect. This suggests that reporting consumer purchase statistics can help mass-market products without hurting niche products. Our results also reveal that the sales impact of observational learning increases with WOM volume.