ChatGPT Ads swaps Max Bid and Max CPC for average cost targets
OpenAI is retiring the maximum bid and maximum CPC caps in ChatGPT Ads and replacing them with average cost targets. Advertisers building conversion campaigns can set a Target CPA from 9 November, and click campaigns can use a Target CPC. Max Bid and Max CPC stop applying to existing campaigns on 1 January 2027.
The targets are goals rather than ceilings. OpenAI's bidding documentation says the system can bid above or below the target in individual auctions to deliver as many clicks or conversions as possible within budget, so any single result may cost more or less than the figure set. Setting a target well below recent performance can restrict delivery and leave budget unspent, and a Target CPA campaign can still be billed on clicks or impressions depending on the billing event chosen.
API partners get new Target CPA and Target CPC fields, and from 18 November any Max Bid or Max CPC value sent through the old fields to create a campaign or change an ad group's bid type will be treated as an average target. The legacy fields stay active until the end of December and are deprecated on 1 January 2027, so integrations need updating before then. OpenAI advises setting targets from recent actual CPA or CPC averages and monitoring real average costs as campaigns learn.
The change matters for brands using paid ChatGPT placements to earn visibility alongside organic citations in AI answers: bidding shifts from capping each auction to steering an average, which puts more weight on conversion data quality and on checking which bid fields third-party buying tools send after 18 November.
Reported by Search Engine Journal ↗
Topics: ChatGPT, AI advertising, Measurement