FTC and 22 states sue Amazon over secret ad surcharge scheme

The regulator that runs consumer protection in the US now says Amazon's ad auction was not what advertisers were told it was. For sellers who have spent years explaining a creeping ACOS to themselves, that is an uncomfortable sentence to read.

What happened

On August 31, 2026 the Federal Trade Commission, joined by 22 state attorneys general, sued Amazon over what it calls a secret ad surcharge scheme, alleging the company engaged in deceptive and unfair practices that secretly inflated prices in its online ad auctions (Federal Trade Commission, August 31, 2026).

The complaint says Amazon "secretly and systematically overcharged" advertisers and may have taken more than $20 billion from them through hidden surcharges (CNBC, August 31, 2026). Coverage of the filing sets out the scope: Sponsored Products, Sponsored Brands and display advertising, in the period after Amazon changed its auction rules in 2019 (TechCrunch, August 31, 2026).

Texas filed a separate state action against Amazon the same day. None of this has been tested in court. These are allegations, and a case of this size takes years.

Why it matters

Every ad platform is a black box to the buyer. You submit a bid, you get a cost, and you trust that the number between them was produced by the rules you were shown. The allegation here is that the rules and the number diverged for years, which is a different problem from a competitive auction getting expensive.

For sellers, the practical consequence is not a refund. It is a reminder that platform-reported efficiency metrics are the platform's own account of itself. Blended ACOS across a catalogue hides a lot: a handful of SKUs carrying the spend, a long tail spending without selling, and auction-level distortion that never surfaces in an account-level average.

What to check this week

1. Read ad cost per unit sold, per product. Not spend, not ACOS. What each unit cost you in advertising before it produced any profit.
2. Rank SKUs by ad spend as a share of contribution margin. The ones above your threshold are the ones a price change in the auction hits first.
3. Track the trend, not the month. A structural shift in auction pricing looks like a slow drift in cost per click at flat conversion. A seasonal one snaps back.
4. Keep FBM SKUs in the same view. Fulfilment method does not change how the auction charges you, and splitting the analysis by it hides catalogue-wide movement.

The Nova angle

Nova joins product-level ad spend to reconciled settlement data, so ad cost sits in the same P&L line as fees, refunds and COGS instead of in a separate advertising console. See Nova PPC analytics and Nova Profit & Loss.