https://www.techdirt.com/articles/20200819/11155045147/content-moderation-case-study-amazons-attempt-to-remove-sock-puppet-reviews-results-deletion-legitimate-reviews-november-2012.shtml

Summary: As is the case on any site where consumer products are sold, there's always the chance review scores will be artificially inflated by bogus reviews using fake accounts, often described as "sock puppets."

Legitimate reviews are organic, prompted by a buyer's experience with a product. "Sock puppets," on the other hand, are bogus accounts created for the purpose of inflating the number of positive (or -- in the case of a competitor -- negative) reviews for a seller's product. Often, they're created by the seller themself. Sometimes these faux reviews are purchased from third parties. "Sock puppet" activity isn't limited to product reviews. The same behavior has been detected in comment threads and on social media platforms.