September 2026 Amazon News: An Ad Auction Lawsuit, ChatGPT Ads and a New Variation Theme

September 2026 produced the most consequential Amazon advertising story in years, and it was not a product launch. On 31 August, the Federal Trade Commission and 22 state attorneys general sued Amazon over the pricing mechanics of its search advertising auctions, alleging a hidden surcharge that ran for more than seven years.

The same month, Amazon opened ChatGPT ad inventory through its DSP, introduced a new quantity variation theme, and confirmed Prime Big Deal Days for 6–7 October. Every one of those changes is still in force heading into Black Friday. Here is what actually happened, what is confirmed, and what remains allegation.

1. The FTC Lawsuit: The Core Allegation

The scale is what makes the case unusual. The complaint covers more than one million brands and sellers, including over 500,000 small and medium-sized businesses, across Sponsored Products, Sponsored Brands and Display ads — the same campaign types most sellers run every day without thinking about them.

2. The Mechanism: What a “Soft Reserve Price” Is

To understand the allegation, you need to understand two auction designs.

In a generalised second-price auction, the industry standard for digital advertising, the winner pays one cent more than the next-highest bidder. That structure encourages honest bidding, because you cannot overpay relative to the market. In a first-price auction, the winner pays exactly what they bid. Bidders respond by shading their bids downward to avoid overpaying.

The FTC alleges Amazon told advertisers it ran a second-price auction, then changed the rules.

• In 2019, according to the complaint, Amazon added an undisclosed surcharge it referred to internally as a “soft reserve price”.
• One internal Amazon document quoted in the complaint describes the auction as having “a surcharge hidden in it”.
• The FTC characterises Amazon’s “invented auction participant” and “proxy 2nd price” bids as effectively shill bids.

The practical result, the FTC alleges, is that a nominally second-price auction was converted into a first-price auction without advertisers being told.

3. The Numbers Behind the Complaint

The complaint’s most quotable figures trace how often Sponsored Products advertisers ended up paying their own full winning bid.

The complaint further alleges that Amazon applied larger surcharges on high-volume shopping days such as Prime Day and Black Friday, and ramped them up gradually in the days before each event specifically to disguise the increase from advertisers. It also alleges the scheme generated $20 billion or more in advertiser costs.

Note: Every figure in this section is an allegation contained in a legal complaint. Amazon denies the claims, the case is unresolved, and no court has made a finding. Content published on this subject must attribute the numbers to the FTC, not to Amazon.

4. Amazon’s Response

Amazon denied wrongdoing in a blog post published the same day the suit was filed, and gave Reuters a set of counter-numbers that are just as specific as the FTC’s.

• Amazon says average cost per click stayed flat from 2019 to 2024, while sales generated from those clicks increased.
• Amazon says average winning bids on Sponsored Products search ads fell 50% from 2019 to 2025.
• Amazon estimates its relevance-based auctions saved advertisers about $8 billion between 2021 and 2025.

On the mechanism itself, Amazon draws a distinction between two kinds of reserve. A hard reserve covers Amazon’s cost of running the placement. A soft reserve is Amazon’s estimate of that placement’s market value. According to Amazon, a winning advertiser pays the soft reserve when its bid clears both thresholds, and pays its own bid when the bid clears only the hard reserve.

Whether that explanation is persuasive is now a matter for the court. What matters for sellers today is that both sides agree on one thing: the auction has thresholds beyond the next-highest bid, and bidding strategy has to account for them.

5. Where the Case Stands and What Happens Next

The case is pending. There is no ruling, no damages figure, and no admission. The states could seek civil penalties and attempt to recover part of the alleged amount. The FTC’s broader history with Amazon provides context: a $2.5 billion Prime settlement in September 2025, and a separate antitrust case expected to go to trial next year.

For sellers, the practical implication is not immediate financial recovery. It is that a set of assumptions about ad pricing has been placed in question. Any historical benchmark that treats Amazon’s auction as textbook second-price should be read with a caveat from here on.

6. ChatGPT Ads Arrive Through Amazon DSP

• Marketplace: United States only at launch, limited to select advertisers.
• Formats: text and image units labelled as sponsored, appearing below ChatGPT responses.
• Pricing: available on a cost-per-click or cost-per-thousand-impressions basis.
• Reporting: aggregated impressions, clicks, cost per result, CPM and CPC.
• Early participant: Delta Vacations is among the first US brands testing the integration.

The scale numbers make the strategic intent obvious. ChatGPT ads reached a $1 billion annualised revenue run rate in late August 2026, with tens of thousands of advertisers. Amazon’s own ad business neared $70 billion in revenue last year — far larger than the retail media networks OpenAI had previously worked with.

There is a notable reversal buried in the announcement. Amazon has historically been protective about letting AI platforms near its store while it built its own shopping tools. Offering advertisers a managed path into ChatGPT is a vote of confidence in conversational commerce as a demand channel — and a decision to be the buying layer rather than the excluded marketplace.

7. A New Total Product Quantity Variation Theme

Amazon introduced a total product quantity variation theme that separates quantity from attributes like size and colour, so shoppers can compare “how much” before comparing “which one”.

• Single packs display as “X count”.
• Multipacks display as “X count (Y packs of Z)”.
• Sellers enter a unit count (total individual units) and a number of packs.

The mechanics are simple, and that is the risk. Three packs of 24 batteries is a unit count of 72 with 3 packs, not a unit count of 3. Invert the two fields and your listing tells every shopper they are buying three batteries instead of seventy-two. Any seller adopting the theme should build a quantity map per child ASIN and reconcile it against titles, bullets, images and carton labels before switching.

8. Prime Big Deal Days Sets the Q4 Calendar

The event is now behind us, which makes it a data source rather than a deadline. The useful question is what the October event revealed about demand heading into Black Friday on 27 November and Cyber Monday on 30 November. Sellers who treat Prime Big Deal Days as a rehearsal — measuring conversion rate, ad efficiency and stock depletion at event pricing — enter November with real numbers instead of projections.

9. The “Increase Conversions” Beta and Sponsored Brands Collections

Amazon Ads also launched an “increase conversions” beta inside the Sponsored Products campaign builder. When selected, it creates a complementary Sponsored Brands campaign in the collections format, with collections able to feature up to 10 products and Amazon selecting which products each shopper sees.

It arrives alongside Amazon phasing out Product Collection ads, which makes the move toward the newer Collections format more than cosmetic. The feature is a beta and availability varies by account; it is significant less for what it does today than for what it signals. Amazon is beginning to treat campaign types as connected steps in one workflow rather than isolated products a seller assembles by hand.

10. Seller Assistant Gets a Plugin

The month closed with an upgrade to Seller Assistant and a plugin connecting Seller Central data to Amazon Quick and Anthropic’s Claude, allowing sellers to automate routine tasks and analyse their own account data inside tools they already use. Amazon highlighted the change at Accelerate 2026; the full set of conference announcements is covered in our separate Accelerate update.

11. FTC Ad Auction Lawsuit: What It Means for Your Q4 Amazon Ad Budget

Four of the six stories in September share a theme: the cost and mechanics of attention are being reworked. Ad auctions are under legal scrutiny, a new conversational surface has opened, catalog data is being standardised, and campaign creation is being automated. Sellers who treat these as separate headlines will miss the connection.

12. Dates to Put on the Calendar

• 31 August 2026 — FTC and 22 states file suit against Amazon.
• 10 September 2026 — ChatGPT ad inventory opens through Amazon DSP (US pilot).
• 6–7 October 2026 — Prime Big Deal Days.
• 27 November 2026 — Black Friday.
• 30 November 2026 — Cyber Monday.
• Pending — FTC case; no ruling or damages announced.