Effects of different eWOM supplementary forms on purchase intention: The moderating role of eWOM valence

With the development of Internet, online shopping has become a trend and is preferred by more and more consumers. Electronic word of mouth (eWOM) plays an important role in online shopping, which helps consumer make an optimal and reasonable purchase decision. Results of previous studies are inconsistent: while the majority of prior research showed that negative eWOM had a stronger influence on purchase intention than positive eWOM, there was some evidence showing the reverse results. Further, studies have found that consumers were more likely to be persuaded by information with high credibility. We propose that supplementary eWOM may be more credible when shopping online in terms of the form. Based on the Cue Consistency Theory and the Theory of Cognitive Dissonance, the present study examined how the forms of supplementary eWOM and eWOM valence affect purchase intention. Two pretests and a main laboratory experiment were conducted. First, we ran two pretests to select the specific materials to be used in the main experiment, which would be used to indicate essential attributes for Smartphones. One hundred undergraduate students (50 for each pretest) participated in the pretests. We then manipulated the eWOM of Smartphone in the main experiment to explore how different supplementary forms (no supplementary reviews vs. consistent supplementary reviews vs. inconsistent supplementary reviews) and eWOM valence (positive vs. negative) influence purchase intention. One hundred and fifty one undergraduates were randomly assigned to seven groups and read reviews with various supplementary forms and different valence. They were first asked to read instructions and imagine that they needed to buy a Smartphone. Then they were presented with some reviews about the Smartphone. Finally, they completed a series of questionnaires measuring perceive usefulness, purchase intention, recommendation intention, satisfaction, regulation focus, dispositional optimism, and demographic information. The results showed that eWOM valence moderated the effect of supplementary forms on purchase intention. Specifically, under positive eWOM, purchase intention in the inconsistent supplementary reviews condition was lower than that in the consistent supplementary reviews condition and that in the condition without supplementary reviews, while no difference was found between the latter two conditions. However, under negative eWOM, purchasing intention showed no significant differences across three conditions. The results also revealed a mediated moderation. First, a significant interaction between supplementary forms and valence on purchase intention ( X → Y was moderated) was found. Second, a significant interaction between supplementary forms and valence on satisfaction was also shown, suggesting that the mediation model ( X → Med ) was moderated. Third, satisfaction had a significant effect on purchase intention ( Med → Y ), and the direct effect of interaction between supplementary forms and valence was reduced, but still significant. A bootstrapping analysis also verified this mediated moderation. Comparing with prior studies on eWOM, our results suggested the different effects of supplementary reviews on purchase intention, which had received little attention. Furthermore, we also found a mediated moderation effect, verifying the mediating role of satisfaction. The findings provide effective suggestions for practitioners in E-commerce marketing on how to manage supplementary reviews practically.