Uncertainty-reduction or reciprocity? Understanding the effects of a platform-initiated reviewer incentive program on regular review generation
Date
2021
DOI
Authors
Pu, Jingchuan
Kwark, Young
Han, Sang-Pil
Gu, Bin
Ye, Qiang
Version
First author draft
OA Version
Citation
Jingchuan Pu, Young Kwark, Sang-Pil Han, Bin Gu, Qiang Ye. "Uncertainty-Reduction or Reciprocity? Understanding the Effects of a Platform-Initiated Reviewer Incentive Program on Regular Review Generation."
Abstract
To stimulate product reviews, many e-commerce platforms have launched reviewer incentive programs in
which free product samples are provided to reviewers in exchange for their ratings of the samples. This
study focuses on an unexplored aspect of reviewer incentive programs—the impact of participating in such
programs on reviewers’ ratings of products they purchased normally (i.e., regular ratings). We find that
after reviewers join the program and receive free product samples, their average regular rating increases by
2.25% (i.e., 0.093 more stars on the five-star scale). Our follow-up analyses indicate that the observed
regular-rating increase can be attributed to an uncertainty-reduction effect evoked by the free product
samples, as opposed to a reciprocity effect. We further delve into the underlying mechanism by analyzing
the reviewers’ regular ratings at a granular, product-category level. Consistent with our theorization of the
uncertainty-reduction effect, our findings reveal that reviewers’ regular-rating increase is driven by
improved assessment and knowledge about products sharing common attributes with the sampled products,
resulting in better post-purchase outcomes. Our results demonstrate that apart from motivating the feedback
for the sampled products, free product sampling can reduce reviewers’ product uncertainty and trigger
evident change in their regular ratings for the purchased products.