When an account has search campaigns and Performance Max at the same time, it is natural for them to compete for the same demand. Cannibalisation generates confusion in reports and can waste budget. Understanding how the system distributes auctions and how to structure the account helps them cooperate instead of compete.
The essentials in a definition
Search and Performance Max can compete for the same searches. The Performance Max documentation explains how the system chooses the campaign for each search, and exact search terms normally take priority in search campaigns when they match. To avoid cannibalisation, define clear roles: search covers explicit intent and brand terms, Performance Max extends reach and formats, with smart bidding and consistent key events in both.
Where they overlap
Performance Max can serve ads on search, display, video, discovery, Gmail and maps. When there are search campaigns with keywords matching the same query, there are priority and relevance rules. In general, search with exact-match keyword tends to take priority on identical queries; check the current official documentation.
The exact priority depends on the platform’s current rules.
Structure for coexistence
Keep search for brand terms, high-intent terms and where you need message and bid control. Use Performance Max to broaden coverage and find additional demand. Exclude from PMax what you do not want (brand, if strategic), using available options. Align feeds, pages and offers.
Define which campaign should cover what.
Search and Performance Max without cannibalisation
- Define who covers what
- Keep brand and high intent in search
- Use PMax to broaden coverage
- Measure the total before and after
Reports and reading
Use search-category and channel reports to understand where PMax serves ads. Compare combined performance before and after adding PMax. Observe the evolution of search impressions, cost and conversions. Beware: part of what PMax attributes could happen in search anyway.
Measure the total, not each campaign in isolation.
Two competent campaigns tripping over each other are worth less than a coordinated structure.
Test and adjust
Test by adding or pausing PMax over comparable periods, or use campaign experiments where available. Adjust budgets so high-intent search is not limited. Review exclusions and negative terms. Document decisions and results for the future.
The good structure is the one that increases the total without duplicating costs.
Decision table
| Element | Search | Performance Max |
|---|---|---|
| Role | Explicit intent and brand | Multichannel reach and discovery |
| Control | Keywords and match types | Signals and assets |
| Exclusions | Negatives per campaign | Brand and URL exclusions, where available |
| Measurement | By term and ad | By channel and asset group, with limits |
Common mistakes to avoid
- Leaving everything overlapping. Costs rise without widening customers.
- Ignoring brand. Brand can inflate Performance Max’s return.
- Comparing only by reported return. Attribution can overvalue the brand campaign.
How to measure the result
Compare new customers, margin and cost per customer by campaign, and check term overlap.
Limits and exceptions
Performance Max behaviour and control options change, and attribution between campaigns is imperfect. Confirm current documentation. Changing structure can restart learning; do it in phases.
Illustrative example
Illustrative example: a store keeps a search campaign for brand and high-intent terms and a Performance Max for the catalogue, with brand exclusions where possible. It compares new customers and margin between structures instead of reported return, and adjusts budgets by each one’s contribution.
In practice: checkpoints
Use experiments to compare structures with and without brand exclusions, record the effect on new customers, and review search-term overlap each month. Avoid changing both structure and budget at the same time, so that you can see what caused any change in results.
Frequently asked questions
Should I run search and PMax?
In many accounts yes, with defined roles and joint measurement.
How do I avoid cannibalisation?
With clear structure, exclusions and reading the total.
Which has priority in auctions?
Check the current official documentation; rules can change.
Should I pause search when using Performance Max?
Not necessarily; test the effect of each structure, carefully and with data.
How do I see the overlap?
With the available search-term and search-category reports.
Define distinct roles for Search and Performance Max, use exclusions, and evaluate by new customers and margin, not reported return.
Sources and recommended reading
Last editorial review: October 2026. Informational content; always confirm current conditions in the official sources before deciding.