Amazon Ads announced a partnership with OpenAI on September 10 that lets advertisers buy ChatGPT ad inventory through Amazon DSP. Select US advertisers are already testing it, with Delta Vacations among the first, and Amazon handling campaign setup and management as a managed service.

The mechanics are worth understanding before the seller-facing implications. Amazon takes your money and places your ads. OpenAI's system decides whether, when, and where those ads actually appear.

What Changed From Everything Before This

ChatGPT has been selling ads since February. What's new is the identity of the seller.

Previously, buying ChatGPT inventory meant dealing with OpenAI directly, through spreadsheets and phone calls at first, then through a self-serve manager that launched in April with a $50,000 minimum. Now a buyer sitting in Amazon DSP can reach a surface Amazon does not own, does not host, and cannot instrument end to end.

That's a notable reversal for a company that has blocked ChatGPT, Claude, and Gemini from accessing its retail ecosystem while building competing AI shopping features of its own.

The Numbers Behind the Deal

ChatGPT advertising crossed a $1 billion annualized run rate in early September, up from roughly $100 million in March. Mobile ad density climbed 163% between April and August. Ads per user per hour on ChatGPT's US mobile app rose an average of 26% month over month from April through August.

Amazon's advertising segment passed $70 billion on a trailing twelve-month basis this year. So the partnership pairs a mature ad business with a fast-growing surface that still lacks basic infrastructure.

The Measurement Problem Hasn't Been Solved

This is the part to weigh carefully before treating ChatGPT ads as a channel worth budget.

Early ChatGPT advertisers couldn't prove measurable business outcomes back in March, with one agency executive pointing out that ads weren't displayed frequently enough to generate assessable data. OpenAI provided clicks and views but not deeper reporting connecting campaigns to actual business results.

Six months later, that gap persists. Nate Elliott, principal analyst at eMarketer, said of OpenAI: “They're still trying to build out even many of the basics of a functional ad sales operation.”

Amazon's involvement improves the buying experience. It doesn't fix attribution, because Amazon can't instrument a surface it doesn't control.

What Sellers Are Actually Asking

The most useful reaction came in the comments on Amazon Ads' own LinkedIn announcement. Abrar Hashmii, founder of ecommerce agency ThriveBizz, wrote: “Big opportunity for sellers. The real question now is how brands will adapt their campaigns and product data for conversational shopping instead of relying only on traditional keyword targeting.”

That's the right question. Keyword targeting assumes a user types a query into a search box. Conversational shopping means someone describes a problem across multiple turns and an AI decides what's relevant. The signals that win in one context aren't obviously the signals that win in the other.

What This Means for Your Ad Strategy

Nothing requires action now. This is a pilot limited to select US advertisers, and Amazon hasn't announced broader availability or a timeline.

When access does open, treat early spend as a test rather than a channel shift. The attribution gap that made ChatGPT ads hard to justify in March hasn't closed, and Amazon's involvement doesn't change who controls the measurement layer.

The preparation that pays off regardless is the same work that improves performance in Amazon's own AI shopping surfaces: complete product data, clear use-case descriptions, and content that answers the questions a shopper would actually ask in conversation rather than the keywords they'd type into a search bar. That work has value whether or not you ever buy a ChatGPT placement.