CPM vs CPC vs oCPC vs Maximize Results: which model to choose on ChatGPT Ads

The comparison table

Two questions to ask, not one

The most common confusion comes from looking for "the right model" as if there were only one choice to make, when there are actually two separate decisions:

1. What to optimize toward? That is the choice between CPM, CPC and oCPC, made at campaign level, irreversible after creation.
2. How to set the bid? That is the choice between manual bidding and Maximize Results, made at ad group level, changeable at any time.

A CPC campaign can therefore run on manual bidding or on Maximize Results; so can an oCPC campaign. The two axes combine, they do not exclude each other.

CPM: when reach comes first

Choose CPM when the goal is to be seen, not clicked: a brand launch, covering an audience, awareness. You pay per impression, in thousands, regardless of clicks. It is the only one of the three objectives that does not depend on any conversion measurement to work properly.

CPC: when traffic is the measure of success

Choose CPC when you want qualified traffic to a site or page, without a conversion measurement in place yet. You only pay for valid clicks. OpenAI recommends a starting bid of $3 to $5 per click. It is the most versatile objective, and the one with the fewest technical prerequisites.

oCPC: when conversion is measured

Choose oCPC when conversion tracking is already operational: pixel, Conversions API, or both, with exactly one active standard conversion event as the goal. oCPC optimizes delivery toward the people most likely to convert, while still billing per click, not per conversion. Without measurement in place, this objective has nothing to optimize toward: stay on CPC.

Maximize Results: when volume matters more than unit cost

Once the objective is chosen, turn on or keep Maximize Results (the default on eligible ad groups) when your priority is to get as many results as possible within a given budget, without needing to hold a precise cost per click or per conversion. Switch back to manual bidding as soon as steering a precise unit cost becomes the priority: Maximize Results guarantees no target CPA, CPC or ROAS. Full details on our ChatGPT Ads Maximize Results page.

A full example journey

A small business discovering ChatGPT Ads typically follows this progression, which follows from the product's own logic:

1. Weeks 1-2: CPC objective, manual bidding between $3 and $5, budget set at the daily minimum for its currency (details on our ChatGPT Ads minimum budget by country page), to observe account behavior without depending on a conversion measurement that is not in place yet.
2. Week 3: pixel and a standard conversion event set up, once click volume is judged sufficient.
3. Week 4: switch to oCPC on a new campaign (the objective cannot be converted on an existing campaign), still on manual bidding while calibrating.
4. After that: test Maximize Results on the same objective, once enough conversion history has built up, to compare volume and average cost against manual bidding.