Performance Max optimization tips tend to fall into two camps: vague (“improve your assets”) or outdated (from before brand exclusions and search-term insights existed). This list is the practical middle. Every tip below is something we apply in real Google Ads accounts for ecommerce stores and service businesses, with a concrete example of how to do it and what to look for afterward.
A quick framing before the list. Performance Max is a black box by design, but it is a black box with inputs. You control the conversion goals it optimizes toward, the product feed and assets it builds ads from, the signals and search themes that steer it, the exclusions that fence it in, and the campaign structure that decides how budget is split. Almost every lever below touches one of those inputs; none of them require fighting the algorithm.
1. Fix your conversion goals before touching anything else
Performance Max optimizes for whatever is marked as a primary conversion at the campaign or account level. If “Add to cart”, “Page view” and “Purchase” are all primary, the campaign will cheerfully buy a mountain of cart adds. Open the campaign’s conversion goals, keep only Purchase (or Lead/Qualified lead for service businesses) as primary, and set the rest to secondary or observation.
Example: a home-decor store had “Begin checkout” as a primary goal alongside Purchase. Removing it typically shifts delivery toward users who finish checkout, and in accounts like this we usually see a drop in reported “conversions” with a rise in actual revenue. Verify the change with a before-and-after comparison on purchase value, not conversion count.
2. Exclude your brand (and judge PMax on non-brand performance)
By default, Performance Max will serve on searches for your own brand name, which you would have converted anyway through a cheap branded Search campaign. In campaign settings, use brand exclusions (Settings → Brand exclusions, choose or create a brand list) to keep those searches in your dedicated brand campaign. Google documents the feature at About brand exclusions in Performance Max.
After excluding brand, expect reported ROAS to fall. That is not PMax getting worse; it is PMax finally telling the truth about incremental performance. Reset your target ROAS to the new baseline and optimize from there.
3. Split asset groups (or campaigns) by margin, not by product category
One campaign, one asset group, “all products” is the most common structure we see, and it means a 60%-margin bestseller and a 10%-margin clearance SKU share one ROAS target. Use custom labels in your feed (custom_label_0 = “high-margin”, “mid”, “low” or “hero”, “catalog”, “clearance”) and build asset groups or separate campaigns around them. Give high-margin groups a lower target ROAS (they can afford it) and clearance a higher one.
Example: a sports-nutrition store with proteins (high volume, thin margin) and accessories (low volume, fat margin). Two campaigns: “PMax – Protein” with a 500% ROAS target and “PMax – Accessories” at 250%. Each campaign now gets a budget and goal that matches its economics instead of the accessories subsidizing cheap protein clicks.
4. Use feed-only asset groups for pure Shopping-style traffic
If you only add a product feed and no images, videos or text, Performance Max behaves much like a Shopping campaign and mostly serves product listings. Many ecommerce accounts run a feed-only campaign for stable Shopping traffic plus a full-asset campaign for discovery placements (YouTube, Display, Discover, Gmail). This lets you see how much of your result comes from Shopping-style intent versus upper-funnel placements. We compared this to Standard Shopping in Google Shopping vs Performance Max.
5. Add search themes and audience signals, but treat them as hints
Search themes (up to 25 per asset group) tell Google which queries you expect to matter; audience signals (customer lists, website visitors, custom segments built from competitor URLs or search terms) tell it who to start with. Neither is a hard target: Google says themes are treated like broad match and the campaign will expand beyond them. Still, they shorten the learning phase noticeably in new campaigns.
Example: for a plumbing company, search themes like “emergency plumber near me”, “water heater replacement cost”, “boiler repair” plus a customer-list signal from past invoices. See our Google Ads for plumbers guide for the full campaign plan.
6. Read the search terms insights report every week and add negatives
Performance Max now exposes search categories and, in many accounts, individual search terms under Insights → Search terms. Look for three patterns: job seekers (“careers”, “salary”), DIY and informational intent (“how to”, “free”, “manual”), and competitor brands you do not sell. Campaign-level negative keywords are available in PMax settings, so you can block them directly instead of waiting for an account-level list. Our negative keywords list is a good starting file to paste in.
7. Check placement reports and exclude junk
Run the predefined report “Performance Max campaigns placement” (Reports → Predefined → Other → Performance Max campaigns placement). You will usually find children’s apps, obscure games and content farms soaking up impressions. Account-level placement exclusions (Content suitability → Excluded placements) and topic exclusions apply to PMax. Excluding the bottom tier rarely hurts volume and often reduces wasted Display spend.
8. Refresh assets with the strength and performance labels in mind
Inside each asset group, every asset shows a performance label: Low, Good, Best, or Learning. The rule we follow: replace “Low” assets every two to three weeks with new variants, never delete “Best”. Supply the maximum of each type (headlines, long headlines, descriptions, images in all three aspect ratios, and at least one real video). If you do not upload a video, Google auto-generates one from your images and text, and those are usually the weakest creative in the campaign.
Example: a B2B SaaS account whose auto-generated video was getting most of the YouTube impressions. Uploading a simple 15-second product walkthrough and marking the old asset for replacement is the kind of change that typically improves view-through quality and lowers cost per lead from video placements.
9. Give it budget and time, then change one thing at a time
Performance Max needs roughly 2 to 4 weeks and, as a rule of thumb, 30+ conversions a month per campaign to learn properly. Daily budgets below about 10 to 15 times your target CPA starve it. When you change the target ROAS, move it by 10 to 15% at a time and wait two weeks. Changing target, assets and audience signals on the same day means you cannot attribute the result to anything.
For European accounts, also confirm Consent Mode v2 is active. Without it, EU conversions are under-reported and the campaign optimizes on a thinner signal than it should; the setup is covered in our conversion tracking with GA4 guide.
10. Add a second campaign only for a real reason
Duplicate PMax campaigns compete with each other and split learning. Legitimate reasons to add one: different geo with different economics (US vs EU, different currencies and CPC levels), different margin tier (tip 3), a product launch or seasonal push that needs its own budget, or a feed-only versus full-asset split (tip 4). “I want more spend” is not a reason; raise the budget on the existing campaign instead.
Performance Max optimization checklist
| Area | Check | How often |
|---|---|---|
| Conversion goals | Only Purchase / Lead is primary; values and currency correct | At setup, then monthly |
| Brand exclusions | Brand list applied; brand Search campaign running separately | At setup |
| Structure | Asset groups or campaigns split by margin or geo via custom labels | Quarterly |
| Search themes & signals | Up to 25 themes per group; customer list uploaded | Monthly |
| Search terms insights | New negatives added | Weekly |
| Placements | Junk apps and sites excluded | Bi-weekly |
| Assets | “Low” replaced; real video present; all ratios filled | Every 2 to 3 weeks |
| Feed health | No disapprovals; titles optimized; labels current | Weekly |
| Bidding | tROAS / tCPA moved in 10 to 15% steps, two weeks apart | Bi-weekly |
| Budget | At least 10 to 15x target CPA per day | Monthly |
FAQ
How long does Performance Max take to optimize?
Expect two to four weeks of learning after launch or after a significant change, longer in accounts with under 30 conversions a month.
Can I see which placements Performance Max is spending on?
Yes, through the predefined “Performance Max campaigns placement” report, and through channel-level reporting that Google has been rolling out in the campaign interface. Both show impressions by placement; cost detail is more limited.
Should I add negative keywords to Performance Max?
Yes. Campaign-level negatives are available in PMax settings, and account-level negative keyword lists also apply. Focus on job, DIY and irrelevant-brand terms.
Why did my ROAS drop after adding brand exclusions?
Because branded conversions were inflating it. The campaign’s incremental performance did not change; its reporting became honest. Adjust targets to the new baseline.
Is Performance Max worth it for small budgets?
Under roughly €500 to $500 per month it is often better to run Standard Shopping or Search, which need fewer conversions to learn. PMax starts to pay off once an account can supply 30+ conversions a month.
Need help with your campaigns?
If your Performance Max campaign has been running for months with no structure, a Google Ads Audit will show exactly which of these ten levers are untouched and what they are costing. If you are starting from scratch, our Performance Max Setup builds the feed labels, asset groups, exclusions and tracking so the campaign learns on the right signal from day one. You can also request a free mini-audit to get a first read on your account.