Performance Max campaigns promise the world: access to all Google’s advertising inventory, AI-powered optimization, and better results with less manual work. But if you’re seeing disappointing returns, you’re not alone. Most marketers make critical mistakes that sabotage their Performance Max success from day one.
After analysing hundreds of Performance Max campaigns, we’ve identified the seven most common mistakes that are quietly draining your ad budget and how to fix them immediately.
1. Launching with Insufficient Budget (The #1 Campaign Killer)
The Mistake: Starting Performance Max campaigns with budgets under £50 per day.
Performance Max needs substantial data to exit its learning period and start delivering results. Low budgets mean limited data signals, which keeps your campaigns stuck in perpetual learning mode.
The Fix:
- Minimum daily budget of £50+ for any Performance Max campaign
- When increasing budgets, stick to 10-20% increments to maintain spending efficiency
- Consolidate smaller campaigns rather than running multiple underfunded ones
2. Neglecting Your Google Merchant Centre Feed
The Mistake: Running ecommerce Performance Max campaigns with poorly optimized product feeds.
Your Merchant Centre feed is the foundation of your Performance Max success. Missing product information, poor descriptions, and incorrect shipping details will tank your performance before you even start.
The Fix:
- Audit your feed using tools like ChatGPT Shopping Feed Auditor
- Ensure no missing values in critical fields (price, availability, shipping)
- Add detailed product descriptions and high-quality images
- Keep shipping information accurate and up to date
3. Using Generic Creative Assets
The Mistake: Uploading random stock photos and generic video content.
Google’s AI needs context to understand your audience and their commercial intent. Generic assets provide zero valuable signals about who should see your ads.
The Fix:
- Create bespoke images and videos for each campaign theme
- Upload the maximum allowed assets (20 images, 5 videos per asset group)
- Update assets regularly to reflect seasons and promotions
- Monitor the Performance column and remove “low” or “poor” performing assets
4. Incomplete Conversion Tracking Setup
The Mistake: Running Performance Max without proper conversion tracking or enhanced conversions.
Performance Max optimization depends entirely on conversion signals. Without accurate tracking, you’re flying blind.
The Fix:
- Implement Enhanced Conversion Tracking and Server-Side Tracking
- Set only core conversion actions (typically “Purchase”) as primary
- Extend conversion window to 90 days for more data
- Ensure conversion values are properly passed for Value Based Bidding
5. Ignoring Search Themes
The Mistake: Leaving search themes empty or adding just a few generic terms.
Search themes are your biggest relevancy signal in Performance Max campaigns. Many advertisers treat them as optional, missing a massive optimization opportunity.
The Fix:
- Add the maximum 25 search themes per asset group
- Include specific product terms, category names, and relevant synonyms
- Think like your customers – what would they search for?
- Update themes based on seasonal trends and new products
6. Poor Campaign Structure Decisions
The Mistake: Either over-segmenting campaigns or lumping everything together without strategy.
Structure impacts budget allocation and performance optimization. Get it wrong, and you’ll struggle with budget control and asset relevance.
The Fix:
- Only split asset groups into separate campaigns when you need different budget allocation
- Consolidate campaigns with small budgets to leverage more conversion signals
- Create bespoke assets for dedicated landing pages
- Consider separate brand vs. non-brand campaigns for better control
7. Giving Up Too Early
The Mistake: Pausing or abandoning Performance Max campaigns after just a few days of poor performance.
Performance Max campaigns need time to gather data and optimize. Expect at least 2-3 weeks before seeing meaningful results.
The Fix:
- Set realistic expectations for the learning period
- Monitor trends rather than daily fluctuations
- Make incremental bid adjustments (10-20% maximum)
- Focus on weekly and monthly performance patterns
Conclusion
Performance Max isn’t a “set it and forget it” solution, but when optimized correctly, it can significantly expand your reach and improve your advertising efficiency. Fix these seven common mistakes, and you’ll be well on your way to Performance Max success.
The key is patience, proper setup, and continuous optimization. Start with these fundamentals, and you’ll see your Performance Max campaigns transform from budget drains into profit engines.
gmfrem 