The U.S. Federal Trade Commission (FTC), joined by a bipartisan coalition of 22 states, has filed a lawsuit in federal court in the Western District of Washington, alleging that Amazon.com illegally inflated auction prices for advertisers. The agency claims the e-commerce giant systematically manipulated the minimum price required to place ads on its platform, a practice that allegedly cost advertisers US$20 billion or more over seven years.
Allegations of Auction Manipulation
The lawsuit centers on three types of advertisements that run alongside search results: Sponsored Products, Sponsored Brands, and Sponsored Display. According to the FTC, Amazon misled customers regarding its “second priceauction model. While the company ostensibly told advertisers that the winner would pay only
one centmore than the next highest bidder, the FTC alleges that Amazon replaced that price with a higher
soft reserve.” 検察官によれば、この仕組みはAmazonの利益を最大化し、広告主のキャンペーンにおける費用対効果を低下させるように設計されていたという。
FTC Chairman Andrew Ferguson stated in a press release: FTCのAndrew Ferguson委員長は、Amazonには数百万もの広告主が存在し、彼らは誤った情報に基づいて不当に高い料金を支払わされていたと指摘した。また同委員長は、こうしたコスト増の大部分は結果として米国の消費者に転嫁されていたと主張した。 The agency alleges that Amazon intervened in as much as 80% of sponsored products auctions. Furthermore, the FTC claims that Amazon sometimes entered its own bids in these auctions to raise prices for others, while attempting to conceal those bids from the advertisers. The agency is seeking tens of billions
in damages, though a precise amount has not yet been settled.
Amazon’s Response and Defense
Amazon has denied the allegations, characterizing the lawsuit as “misguidedand stating the FTC
fundamentally misunderstands how advertisers operate.” In a blog post, the company argued that its advertising policies aim to show shoppers the most relevant ads. Amazon asserted that the average cost per click for advertisers remained flat from 2019 to 2024, while sales generated from those clicks rose. The company further claimed that スポンサープロダクト検索広告における平均落札価格は、2019年から2025年にかけて50パーセント下落したと述べた。
According to Amazon, the company actually reduced costs for advertisers, saving them some $8 billion between 2021 and 2025 by prioritizing ad relevancy over bid price alone. 同社は、Amazonの価格設定に対するアプローチは消費者への不利益を示唆するいかなる主張とも矛盾していると表明した。また同社は、自社は毎日、最も幅広い品揃えの商品を顧客に最低価格で提供しており、小売価格や食料品価格が他社の提供価格と同等かそれ以下になるよう努めていると説明した。
Market Context and Regulatory History
Amazon has aggressively expanded its advertising business, which is now the world’s third-largest behind Google and Meta. The company reported that ad sales rose significantly in the second quarter of this year to US$19 billion and saw growth in all of 2025. In its Q2 filing, Amazon noted that shoppers who click a “Sponsored” prompt convert sales 48% more often and spend 21% more on average than those who do not.
This litigation marks the third time the FTC has brought major legal action against Amazon. In 2023, the FTC sued Amazon for operating a monopoly. Additionally, the FTC previously sued Amazon for allegedly duping customers into enrolling in Prime and making cancellation difficult. In September of last year, Amazon agreed to pay US$2.5-billion in fines and reimbursements to settle those allegations. Following the news of the current lawsuit, Amazon shares fell on Monday.