What is review manipulation by bots?
Short answer: Review manipulation uses fleets of aged buyer accounts to post purchased praise or attack reviews at scale. Because the accounts have real purchase histories - bought, rented, or built through cheap orders - each review passes authenticity checks while the campaign's aggregate pattern is entirely synthetic.
Why verified purchase is not verification
Review farms run real orders through real accounts, often with refund schemes that make the purchase nearly free. The 'verified' badge certifies a transaction happened - not that an opinion exists.
The economics of five stars
On crowded marketplaces, a rating point is worth measurable revenue share. Buying two hundred reviews is cheaper than earning them, so sellers with thin margins buy. Honest sellers subsidize the fraud with their ranking.
Detection in the aggregate
A single farmed review is indistinguishable. A campaign is not: timing clusters, reviewer-graph overlap, product-category drift, linguistic reuse. Scoring the pattern rather than the post removes campaigns while leaving eccentric humans alone.