Influencers: The Power of Comments

Many customers choose products based on information from social media influencers. Companies can pay these influencers to promote their products. We develop a model in which customers read an influencer’s sponsored post for a mix of entertainment and product information, and those who purchase the product can leave comments for future customers. We derive conditions in which a large celebrity influencer endorses all products, whereas a microinfluencer adopts a policy of endorsing only high-quality products. In equilibrium, the microinfluencer screens for high-quality products so his followers do not waste time reading informative comments about low-quality products. By contrast, the celebrity influencer attracts so many uninformative comments his followers do not use his comments as a source of product information, and the value of his endorsement arises solely from generating product awareness.

History: Ganesh Iyer served as the senior editor for this article.

Conflict of Interest Statement: All authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest or nonfinancial interest in the subject matter or materials discussed in this manuscript.

Supplemental Material: The online appendix is available at https://doi.org/10.1287/mksc.2022.0186.