Do not pause Performance Max because brand traffic exists. Separate the demand, apply the appropriate control, and judge the change on total-account non-brand and new-customer outcomes.
Use this resource when
The symptom
PMax reports the best ROAS in the account while brand Search volume or conversions decline. Asset-group reporting looks healthy, but search categories and customer mix suggest the campaign is harvesting existing demand.
The evidence stack
Pull PMax search categories or query insight, brand Search trends, new-customer share, returning-user conversions and total-account conversion volume. Add Merchant Center brand data for commerce accounts. No single report proves cannibalisation.
- Brand query exposure
- Brand Search impression and conversion trend
- New versus existing customer share
- Total account non-brand conversions
- Change in direct and organic branded demand
The controlled change
Create or confirm the correct brand list, apply brand exclusion to the relevant PMax campaign, annotate the change date and keep other material controls stable. Google supports brand exclusions for Performance Max; use negative keywords for essential irrelevant terms, not as a substitute for brand governance.
The measurement window
Read at least one full conversion-lag cycle and compare the same weekday mix. Watch total-account conversions and value, non-brand acquisition, new-customer share and marginal CPA—not PMax ROAS alone.
The decision
Keep the exclusion if total-account acquisition quality is stable or improves and non-brand contribution becomes clearer. Revisit the design if total-account qualified volume falls materially without a compensating quality improvement.
What I would not change
I would not pause PMax, restructure asset groups and change bidding in the same test. Multiple simultaneous edits destroy the evidence needed to decide whether brand control helped.
Practical questions
Questions that change the decision
Does all branded traffic in PMax equal cannibalisation?
No. The question is whether the campaign receives credit for demand that would have converted elsewhere and whether controlling it improves incremental acquisition.
Should competitor brands also be excluded?
Only when they are irrelevant, create policy risk or fail the economics. Competitor intent can be valuable in some categories.
Can I use negative keywords instead?
Google recommends brand exclusions for brand searches. Use negative keywords for essential irrelevant terms or brand-safety needs.
Sources and platform documentation
Platform features change. These links point to the primary documentation used for the implementation details above.