The Maze: The FTC and 22 states have sued Amazon over the machinery behind its sponsored-search prices. The plaintiffs allege that, after ranking ads through a second-price auction, Amazon secretly inserted a higher “soft reserve” and often pulled the winner’s charge up to its maximum bid. Amazon says the reserve reflects placement value, never exceeds the bid and improves relevance. The legal question is not whether Amazon can set a floor. It is whether the platform told more than one million advertisers what set their price.
The lawsuit targets auction truth, not just expensive ads. A second-price auction encourages a brand to bid near its maximum because the winner should owe only enough to beat the next-ranked advertiser. The FTC alleges that Amazon instead calculated a platform-controlled “proxy” price after the competitive result. If advertisers expect the market-clearing amount but often pay their ceiling, they can overstate a click's value while believing a rival set the bill.
Both sides agree a reserve exists; they disagree on what it means. The complaint describes a soft reserve that replaces the generalized second-price result after the auction and says Sponsored Products winners paid their full bid close to 80% of the time in 2024. Amazon explains the same structure differently: ads are ranked by bid and predicted relevance; a hard reserve determines entry; a soft reserve estimates placement value; and a winner can pay its bid when that bid sits below the soft reserve. No advertiser pays above its stated maximum.
The economic fight is disclosure versus observed performance. Regulators say the alleged surcharges affected roughly 1.2 million U.S. advertisers, including more than 500,000 small and medium-sized businesses, and likely generated tens of billions of dollars. Amazon says average cost per click stayed flat after inflation through 2024, winning bids fell 50% by 2025 and advertiser conversion rose 24% from 2021 to 2025. Better return on ad spend can coexist with a pricing rule buyers did not understand.
Retail media turns the marketplace into both referee and bidder designer. Amazon controls the query, ranking, relevance model, auction data and final charge. Sellers cannot reconstruct the rival bid or reserve from aggregated reports. That gap matters because advertising is a variable selling cost embedded in product margin. A few extra cents per click can hide inside healthy sales while changing which products remain profitable.
The remedy could matter more than the headline damages number. The case seeks an injunction and monetary relief; state claims also support penalties, restitution or disgorgement. Liability has not been decided. Operators should watch whether Amazon must disclose reserves, provide clearing-price records, change training language, refund advertisers or alter the mechanism. Any could change bidding models before damages change a quarterly result.
Why it matters: Amazon’s defense is that advertisers set ceilings, watch results and received better performance. The plaintiffs’ answer is that a ceiling is not informed consent to an undisclosed clearing rule. Sellers should preserve campaign and auction records, model margin at full-bid scenarios and separate conversion gains from pricing transparency. This case will test a core retail-media bargain: how much control a marketplace may keep over the auction when it also controls the data needed to audit it.
Sources: Federal Trade Commission | Complaint | Amazon response | Associated Press
