Amazon was just hit with a regulatory legal suit that makes standard ad markups look like pocket change. The FTC and 22 state attorneys general allege that since 2019, the company has secretly skimmed over $20 billion out of advertisers’ pockets by discreetly inflating prices after auctions.
Amazon has pushed back by claiming that the FTC offers no evidence of consumer price increases or advertiser harm. The company has pointed out that its average inflation-adjusted cost per click for Sponsored Products’ search ads remained flat between 2019 and 2024, while conversion performance actually improved.
Legal proceedings like this take years to wind through Seattle federal court. For brands spending millions on Amazon Ads every quarter, waiting for a verdict isn’t a strategy. The case shines a harsh light on automated ad marketplaces where one party sets the rules, runs the auction and reports the final bill.
How The Alleged Post-Auction Markup Worked
Amazon spent years selling advertisers on the fairness of its standard second-price auction system. In theory, the winning bidder never pays their full ceiling, just slightly more than the runner-up. Brands submit their maximum bid, the marketplace runs the numbers – ultimately, the rivalry sets the market rate.
Federal regulators see a differing reality behind the scenes. Regulators allege that starting in 2019, Amazon introduced an undisclosed internal soft reserve or surcharge after the auction cleared. Instead of charging the price determined by open competition, internal systems allegedly swapped in a higher, arbitrarily elevated cost before sending the bill to the advertiser.
The complaint claims that Amazon staff referred to the discrepancy between the actual auction clearing price and the final charge as an auction surcharge. Over six years, regulators have calculated that Amazon illegally extracted more than $20 billion across 1.2 million advertisers using Sponsored Products, Sponsored Brands and Sponsored Display.
The suit further alleges that Amazon used subtle testing to introduce incremental price spikes and brushed off brand inquiries when media buyers questioned unexpected cost spikes.
How Amazon Is Fighting Back
In Amazon’s view, the FTC has a flawed understanding of online ad mechanics. The platform argues that advertisers don’t set bids based on isolated mechanical rules, but rather adjust their spending continuously to match placement quality, conversion performance and bottom-line targets.
Amazon stresses that its relevance-weighted auction model saved advertisers about $8 billion between 2021 and 2025 by favoring high-converting, relevant products over raw bid size. Furthermore, conversion rates grew by 24% over a similar window.
From Amazon’s perspective, advertisers received better value for their money, making claims of systematic financial harm baseless.
The Black Box Dilemma In Modern Retail Media
Whether the courts land on the side of the FTC or Amazon, the case highlights an obvious vulnerability in modern retail media networks. When the auctioneer, the rulebook creator and the reporting engine are all the same company, true price discovery becomes nearly impossible for buyers.
If a platform advertises a second-price model while applying secret post-auction markups, the economic reality changes to a hybrid model without any of the transparency buyers expect. When ad costs jump, brands naturally pass those expenses down the chain.
The FTC contends that these hidden markups trickled into consumer retail prices, effectively taxing every product sold on the marketplace.
Spotting Hidden Anomalies In Your Ad Spend
Brands buying Amazon ads should probably treat this lawsuit as a prompt to run a thorough internal audit instead of waiting for a settlement.
Investigating potential overcharges would require extracting historical data with fine granularity. Analysing daily or hourly metrics across Sponsored Products, Sponsored Brands and Sponsored Display exposes true effective cost per click over time. Dividing overall spend by total clicks brings to light any sudden step-changes that may have occurred without matching adjustments to target keywords, bid ceilings or product margins.
Matching historical bid logs against billed amounts would provide good context, since an abrupt spike in effective cost per click minus a bid increase or a clear surge in competition would point straight to an unannounced pricing shift.
Evaluating pre-2019 baseline metrics against the 2019-2024 window would serves as a direct test of Amazon’s defense, as performance across specific niche categories often diverges sharply from broad platform averages. Requesting written breakdowns from Amazon account representatives regarding how final charges derive from raw auction inputs establishes an official paper trail, while logging responses secures clear documentation on pricing rules and algorithmic shifts.
Re-Evaluating Your Media Spend
The $20 billion claim illustrates why brands cannot treat automated ad platforms as set-and-forget tools. Target returns on ad spend relying on assumed auction fairness is taking an unhedged operational risk.
Evaluating long-term risk means running models that test past campaign performance against unannounced platform fees. Separating ad spend driven by real bidding wars from spend tied to mystery inflation points to true acquisition costs. When those figures don’t add up, brands tend to move capital toward channels with verified auction mechanics and legitimate price transparency.
Programmatic efficiency is great right up until the auctioneer starts discreetly adjusting the tally. Documenting campaign performance and safeguarding bid records would give brands the leverage needed to verify every invoice. Because when billions are on the line, letting a platform mark its own homework is a quick way to buy an expensive lesson.
