ChatGPT Ads kills the max CPC. From January, OpenAI bids for you

Remember the early days of Google Ads and Meta? New channel, thin data, and the only thing protecting you from expensive clicks was your max bid. That's exactly the tool OpenAI is now taking away from advertisers. Politely, with a transition period. But firmly.

What happened

• Since November 9: New conversion campaigns in ChatGPT Ads Manager run on Target CPA, new click campaigns on Target CPC. "Maximize results" is now called Intelligent bidding.
• From January 1, 2027: Max Bid and Max CPC stop applying to existing campaigns too. Until then you can switch yourself.
• For API partners from November 18: According to Search Engine Journal, values sent in the old Max Bid and Max CPC fields are read as average targets, not caps. The legacy fields stay active until the end of December.
• Targets are averages: OpenAI says the system may bid above or below your target in individual auctions. OpenAI's own example: $400 spend, 10 purchases, so a $40 CPA. A $20 target doesn't guarantee purchases at $20 each.

The real change is in the fine print

Here's the part that isn't in the headlines. OpenAI's help page now states plainly that the final winning auction bid sets the price you pay. As recently as early November, per Search Engine Journal, the basics page described a relevance-weighted second-price auction. That wording is gone.

Translation: before, at best you paid just above the runner-up, capped by your own maximum. Now the system bids for you, pays what it bids, and only answers to an average. Sounds like a detail. It isn't. The pricing rule and the cap change in the same month, and both move control from you to OpenAI.

Automation needs fuel you don't have yet

My rule from my own Meta tests: never trust the automation blindly. At i4u, Advantage+ with Audience Network delivered almost nothing but junk clicks. Since then I pick placements deliberately. Target CPA systems are only as good as the conversion signal. And that's exactly what's missing in a channel that has only been running in Germany for a few months and only reaches users on the Free and Go tiers.

OpenAI itself says a target set too low can restrict delivery. Set it too high and you pay for it. And for campaigns that get migrated automatically on January 1, OpenAI, according to the reports, doesn't say what target they'll get. Do nothing, and the system decides what a customer is allowed to cost.

The catch

The direction is industry standard. Microsoft Ads, per Search Engine Journal, stopped offering Max CPC on new non-portfolio Target CPA campaigns from October 1. So this isn't about fighting it. It's about who sets the starting number.

What I'd do now

• Switch before January 1 yourself. Derive the target from your actual results of the last few weeks, not from the dream CPA in the business plan.
• Check conversion tracking before using Target CPA. Without clean signals, stick to click campaigns on Target CPC with a small budget.
• Your daily budget is your new cap. Look at actual click prices weekly, not just the average. Set one clear rule for who may change targets.

I still think testing ChatGPT Ads early is right when Google and Meta stop moving the needle. But with your own starting number, not the machine's.

Bottom line: If you haven't set your own target by January 1, you've just handed OpenAI your price tag.