Common Performance Max Mistakes in 2026 (Yes, These Still Happen)

By 2026, Performance Max mistakes are rarely technical. They’re strategic. The platform does exactly what it’s told — sometimes a little too well.

Here are the most common Performance Max optimisation mistakes we still see, with examples that explain why results go sideways.

Mistake #1: One Performance Max Campaign Doing Everything

Trying to make one Performance Max campaign handle every goal usually leads to confused delivery and inflated CPAs.

What typically happens:

1. Google prioritises the easiest conversions (usually brand traffic)
2. Prospecting gets underfunded
3. Reporting becomes impossible to interpret.
   

Mistake #2: Letting Auto-Created Assets Run the Show



Auto-created assets are useful — until they become the only assets.

Common symptoms include:

A. Generic headlines with zero differentiation
B. Auto-generated videos made from stock images
C. Ads that technically exist but emotionally don’t

Mistake #3: Optimising for the Wrong Conversions

Performance Max will optimise for whatever you define as success — even if that success is meaningless.

The most common offenders:

• Newsletter signups
  
• Low-intent contact forms
  
• Pageview-based micro conversions

One service-based account removed low-quality actions from its primary optimisation goal and focused only on revenue-driving leads.

The result:

A. Revenue per lead increased 41%
B. CPA increased slightly (+6%)
C. Sales team complaints decreased dramatically (rare but powerful metric)

Optimising for low-intent conversions is like giving your campaign a gold star ⭐ every time someone looks at the homework instead of doing it.

Mistake #4: Never Refreshing Creative

Performance Max doesn’t get bored. Audiences do.

Accounts that leave creative untouched for months typically see:

1. Gradual CPA creep
2. Falling CTR
3. “Performance just dropped for no reason” conversations

A DTC brand refreshing creative every 30–45 days saw:

• Spend scale +62%
  
• CPA remain stable
  
• Performance recover without touching bidding
  

Mistake #5: Blindly Applying Google Recommendations

Recommendations are suggestions — not commandments.

Following every recommendation often leads to:

A. Budget increases
B. Broader targeting
C. Less control, not more performance

One advertiser applied all recommendations for 30 days:

• Spend increased 45%
• Conversions rose 12%
• CPA worsened 29%
  
  

Rolling back non-essential changes restored performance within two weeks.