Performance Max: what it is, how it works and how to control it

Performance Max (PMax) is the Google Ads campaign type that can serve ads across all of Google's inventory from a single campaign: according to the official help page, on YouTube, Display, Search, Discover, Gmail and Maps. It is designed to complement your keyword-based Search campaigns, not simply replace them. Bidding, targeting and creative combinations are decided by the system based on your conversion goal, the assets you supply and the signals you give it.

What Performance Max is and when to use it

Google recommends it for advertisers with specific conversion goals who want to reach every channel from one campaign. The available objectives are Sales, Leads, Website traffic and Local store visits. It works best when conversion measurement is reliable: if the system optimises towards a badly defined conversion, it will optimise very well towards something you don't want.

How a campaign is organised

The working unit is the asset group: a set of headlines, images, videos and a final URL that the system combines into ads for each placement. Each group can carry its own audience signals (your customer lists, custom segments, interests) and search themes. Neither restricts targeting: they are hints that help the system learn faster.

• One asset group per theme or product line, not per channel: the system picks the channel.
• Audience signals built on your own data first (customers, converting visitors), then custom segments.
• Search themes to indicate which queries are relevant when your website doesn't make it obvious.

How it coexists with your Search campaigns

This is the most common question. According to the official documentation, if a query exactly matches an exact-match keyword in an eligible Search campaign, the Search campaign takes priority. PMax search themes have the same priority as phrase- or broad-match keywords. In practice: protect your key terms with exact match in Search and leave the rest of the inventory to PMax.

The controls you do have

PMax is known as a "black box", but it now offers quite a few levers. The official help lists negative keywords, brand exclusions, Final URL expansion (which you can turn off so it only uses the URLs you specify), text customisation and, since October 2026, channel prioritisation.

Channel prioritisation and budget allocation

Google's 14 October 2026 announcement introduces two optional controls for Search, Shopping, Performance Max and Demand Gen: marking inventory as high or low priority and setting a maximum percentage of the daily budget for low-priority channels. In PMax and Demand Gen, Google surfaces (Search, YouTube, Maps, Gmail and Discover) are prioritised together as "Google channels". The cap is applied on a best-effort basis and is rolling out over the coming months.

Which reports to check every week

1. Channel performance: where the money goes and what conversions each surface brings.
2. Assets and asset groups: which pieces work and which need replacing.
3. Placements: where your ads have appeared.
4. Budget panel: low, medium and high budget recommendations based on expected performance.

Pre-launch checklist

• A well-defined primary conversion, ideally with a value (enhanced conversions on).
• Brand and key-term Search campaigns on exact match.
• Brand exclusions and negatives ready.
• A decision on Final URL expansion versus your own URLs only.
• Enough assets in each group: text, images and, ideally, your own video.
• Channel priority reviewed once it reaches your account.