Amazon's ad business just moved into the conversation where more shoppers are deciding what to buy, with a September 10 pilot that lets select US advertisers buy ChatGPT ads through Amazon DSP as a managed service. The timing tracks with where Amazon ad budgets are already heading, with Sponsored Brands clicks down 10% in Q1 2026 while CPCs rose 14%, and DSP spend up 67% year over year in Q2, its fastest rate since 2021. ChatGPT is the newest surface in a strategy Amazon has been running since mid-2025, one built on the fact that Amazon's own inventory can only grow so far.

The sequence started with Roku in June 2025, where custom identity resolution let Amazon DSP recognize logged-in viewers across Roku OS, followed a day later by Disney wiring DRAX into Amazon DSP across Disney+, Hulu and ESPN. Netflix came in September 2025, and Amazon Audiences were applied directly to Netflix inventory in the US in April 2026 and across five EMEA markets in May. SiriusXM, Pandora, SoundCloud and Spotify, across nine markets, followed, and Microsoft named Amazon DSP the preferred transition partner for Microsoft Invest customers. ChatGPT is the latest name on that list.

The growth is happening off Amazon

Amazon DSP's 67% growth in Q2 came with impressions up 60% against a 4% CPM increase, which is supply expanding faster than demand can price it. The DSP now accounts for 44% of Amazon spend among advertisers using both the DSP and the ad console, up from 32% in Q4 2024. Prime Video impressions grew 56% while CPMs fell 5%, and Amazon put Prime Video's global ad-supported reach above 315 million monthly viewers in November 2025, up from 200 million in April 2024.

On Amazon itself, the Q1 click decline is part of a longer pattern, with Q2 bringing a fifth consecutive quarter of double-digit CPC increases on Sponsored Brands on only 4% click growth, which is how inventory behaves once it has hit its ceiling. Across the category, eMarketer forecast off-site retail media growing 42.1% in 2025 against 15.1% for on-site. Any retail media network built on a retailer's own site eventually runs into finite search results, finite product pages and a finite pool of shoppers, so the path to scaling Amazon's ads business runs through everyone else's screens.

Amazon is selling its read on the shopper

The asset that travels in every one of these deals is Amazon's read on the shopper, applied to someone else's screen. Netflix, Roku and now ChatGPT gain sharper targeting, Amazon collects a toll on each transaction, and every new partner feeds a loop that makes that read more accurate for the next one.

The model mirrors AWS, which grew by becoming the infrastructure other websites run on, and Amazon Ads is positioning itself the same way as the layer underneath whichever publisher wins the impression. Retail Ad Service makes the strategy explicit, since Amazon is already operating the ad stack for competing retailers there.

Why ChatGPT, and why now

Shopping research is moving into AI assistants quickly enough to make ChatGPT an obvious next partner. Adobe's March 2026 survey of more than 5,000 respondents found 39% of US consumers have used AI assistants for online shopping, rising to 53% among Gen Z, and PwC found 29% plan to use AI for holiday shopping this year, up from 22% last year. ChatGPT passed a billion weekly users in July 2026.

The traffic quality has caught up with the volume. Adobe puts AI-referred retail traffic up 138% year over year as of May 2026, converting 54% better than non-AI traffic with 53% higher revenue per visit and 36% lower bounce, a full reversal from twelve months earlier, when non-AI traffic converted nearly twice as well. Salesforce found AI-search shoppers converted nine times more often than social referrals over the 2025 holiday.

The pairing retail media has been chasing

Purchase history is the strongest predictor of what someone buys next, and a conversational query is the clearest statement of what they are trying to solve right now. A shopper who types "best running shoes for flat feet, I'm training for a half marathon" into ChatGPT has handed over intent no keyword could capture, and Amazon holds years of purchase data on shoppers like that one.

How much of that pairing exists inside the pilot today is still an open question. OpenAI's systems control placement, neither company has detailed which Amazon signals inform targeting in ChatGPT, and with the FTC and 22 states currently alleging Amazon overcharged advertisers in its auctions, buyers will reasonably want that transparency before scaling spend. The direction is clear enough, and it puts Amazon closer to connecting purchase history with live conversational intent than any other platform.

Across our retail media clients, we're building normalized measurement frameworks that align holdout design, lookback windows and conversion definitions across Amazon DSP and other retail media partners, and the ChatGPT pilot is exactly the kind of new placement that framework is built for. For brands revisiting whether their Amazon allocation still reflects a world where on-site was the only option, setting that measurement up before the first ChatGPT impression serves is what makes the results comparable to the rest of the plan.