Performance Max can be a strong performer, it finds conversions across Search, Shopping, YouTube, Display and Gmail from a single campaign. The catch: left alone, it tends to spend a meaningful slice of budget on people already searching your brand. That's traffic you'd win anyway, now bought at a premium.
Why it happens
PMax optimises for conversions, and branded searches convert cheaply and reliably, so the algorithm leans into them. Your blended CPA looks fantastic while non brand discovery, the reason you ran PMax in the first place, quietly gets less oxygen.
How to keep control
- Use brand exclusions to stop PMax serving on your own brand terms where appropriate.
- Watch the share of PMax spend going to branded queries over time.
- Keep a clear view of brand vs non brand performance instead of one blended number.
- Set budget guardrails so PMax can't quietly crowd out the rest of the account.
Don't throw it out, steer it
The answer isn't to abandon Performance Max; it's to give it boundaries. Exclude the traffic you'd win for free, measure brand and non brand separately, and reallocate the budget you recover into the discovery PMax is genuinely good at.