TL;DR
Performance Max is Google's most powerful — and most misunderstood — campaign type. Here's exactly how to run it correctly for maximum ROAS.
→ See how this applies to your business (free 30-min call)Performance Max became mandatory for most Google Ads campaigns in 2024. Most advertisers are running it wrong. Here's what we've learned managing it across dozens of accounts.
What Performance Max Actually Is
Performance Max (PMax) is Google's fully automated campaign type that serves ads across all Google inventory simultaneously: Search, Display, YouTube, Gmail, Maps, and Discover. You provide assets — headlines, descriptions, images, videos, audience signals — and Google's AI determines where, when, and to whom to show your ads.
The promise: maximum reach, maximum automation, maximum ROAS. The reality: if you set it up wrong, you get maximum waste.
The Setup Mistakes That Kill Performance
Mistake 1: One asset group for everything
Most advertisers create one PMax campaign with one asset group containing all their assets. Google then mixes them randomly across all placements. The result: generic ads with no message-to-market match.
The correct approach: create separate asset groups for each distinct product or service, with assets specifically written for that offering and audience.
Mistake 2: No audience signals
Audience signals are the most underutilized feature in PMax. These aren't targeting restrictions — they're suggestions to Google's AI about who to prioritize when learning. Without them, PMax spends weeks or months in a learning phase burning budget on irrelevant traffic.
Use: Customer match lists (upload your CRM), website visitor lists, custom intent audiences, and competitor keyword lists as audience signals.
Mistake 3: Ignoring search themes
Search themes (added in 2023) tell PMax which search queries you want to appear for. Without them, PMax guesses — and often guesses wrong, appearing for tangentially related queries that convert poorly.
Mistake 4: No brand exclusions
By default, PMax will bid on your brand terms — traffic that would have found you organically anyway. This inflates your conversion numbers while providing little incremental value. Always add brand exclusions.
The Asset Strategy That Works
PMax performance is almost entirely determined by asset quality and variety. Google's AI needs enough variety to test effectively and find the combinations that convert.
Headlines: Minimum 15, ideally 20+. Mix benefit-focused, feature-focused, and urgency-focused. Include primary keywords in at least 3 headlines.
Descriptions: 4 minimum, 6 ideal. Each should focus on a distinct value proposition.
Images: All recommended sizes — square (1:1), landscape (1.91:1), and portrait (4:5). At minimum 5 of each. More variety = more testing = better performance.
Videos: If you don't provide video, Google will auto-generate them from your images. These are almost always low quality. Provide your own 15-second and 30-second videos.
Bidding Strategy
New PMax campaigns should start with Maximize Conversions (no target ROAS) for the first 4–6 weeks. This allows the algorithm to gather conversion data without the constraint of a ROAS target.
Once you have 50+ conversions in the campaign, switch to Target ROAS. Start with a target 15–20% below your actual historical ROAS to give the algorithm room to work, then tighten it gradually as performance stabilizes.
Never set a Target ROAS that's significantly higher than your historical average — the campaign will restrict spend so aggressively that it can't gather enough data to optimize.
What to Monitor
PMax has limited transparency by design. The most important metrics to watch:
Search terms report — Available under Insights. Review weekly for irrelevant queries and add negatives through the campaign-level negative keyword list.
Asset performance ratings — Low-performing assets should be replaced, not kept. Google rates each asset as Low/Good/Best. Replace Low assets every 2–3 weeks.
Audience insights — Shows which audiences are converting. Use this to inform your broader marketing strategy.
Placement exclusions — PMax places ads on Display and YouTube by default. Review placement reports and exclude irrelevant sites/channels that are consuming budget.
The Result When Done Right
A retail client running a single PMax campaign with one asset group and no audience signals was achieving 2.1× ROAS. After restructuring into 6 asset groups with audience signals, proper exclusions, and a full asset suite — ROAS climbed to 6.8× over 90 days on the same budget.
The campaign didn't change. The setup did.
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