Performance Max for E-commerce: How to Structure It So Budget Follows Profit
By Jacob Thyssen, Founder of Thyssen Ads
Short answer: Performance Max can be the strongest campaign type in an e-commerce account, but only if you give it boundaries. Exclude your brand so it can't take credit for customers who already know you. Segment the feed by margin and performance so a few best-sellers don't take the whole budget. Send clean, server-side conversion data, and where possible send profit instead of revenue. Then set a target per segment and scale only while the target holds. Left on default settings, Performance Max optimises to whatever is easiest to sell, not to what makes you money.
Performance Max (PMax) is Google's goal-based campaign type that runs across Search, Shopping, YouTube, Display, Discover, Gmail and Maps from one campaign. Google describes it in About Performance Max campaigns. For online shops it's usually built on the Merchant Center feed, so it behaves a lot like Shopping with extra placements.
That's the appeal. It's also the problem. One campaign with one budget and one target, across every channel and every product, means Google decides where the money goes. Sometimes that works. Often it doesn't.
Why Performance Max goes wrong in e-commerce accounts
These are the patterns we see most often when we take over an account:
- Brand inflates the numbers. PMax can serve on brand searches. Returning customers click, buy, and PMax reports a great ROAS for demand it didn't create.
- A few products take everything. The algorithm moves budget to products that already sell. Hundreds of products with potential never get impressions.
- Brand-level structure hides product-level truth. Accent Clothing came to us heavily reliant on Performance Max, with campaigns structured by brand. Strong products were hidden inside weak brands, and weak products drained budget inside strong brands.
- Revenue, not profit. A target ROAS treats a low-margin sale the same as a high-margin one.
- Bad tracking. Duplicate purchase actions or missing conversions teach the algorithm the wrong lessons, faster.
None of this means PMax is bad. It means PMax needs structure.
When to use Performance Max, and when not to
Use Performance Max when:
- Your feed is clean and products are approved.
- Conversion tracking is reliable (ideally server-side, with enhanced conversions).
- You have enough conversion volume per campaign for Smart Bidding to learn.
- You want reach beyond Shopping (YouTube, Discover, Display) without managing each channel.
Prefer Standard Shopping or Search when:
- You need full control over queries and placements for a segment.
- You're testing new products or a new market with little data.
- You need to see exactly which searches drive sales for a product group.
Most of our e-commerce accounts use both. The point is that every campaign has one job. That's what we mean by one job per campaign: a clear role, a clear target and enough data to learn.
How to structure Performance Max for e-commerce
1. Keep brand out
Apply brand exclusions to Performance Max and run brand in its own Search campaign. Brand protects returning customers. PMax should be judged on finding new ones. This is the first rule in our account structure guide: brand and non-brand, always separated.
2. Segment the feed before you segment campaigns
Use custom labels in the feed to group products by:
- Margin band (high, medium, low)
- Performance index (best-sellers, average, zombies with no sales)
- Price band, where order value changes what you can pay per click
Then build PMax campaigns around segments that need different targets. High-margin best-sellers can run at a lower ROAS target. Low-margin products need a higher one. Zombie products may need their own campaign or Standard Shopping to get any visibility at all.
For Hundlands, we added a daily script that analyses each product's performance and labels it, so budget goes behind the products that perform. With enough data, non-brand budgets in Germany, Austria and Switzerland scaled while ROAS improved. Google Ads ROAS rose 39% even as spend scaled more than sixfold. Read the Hundlands case study.
3. One market per campaign
Different countries have different CPCs, competitors and margins after shipping. Keep markets in separate campaigns so each can have its own budget and target. Roll out one proven structure country by country.
4. Asset groups that match how people shop
Build asset groups around product themes (for example "running shoes" and "trail shoes") rather than one asset group for everything. Give each group relevant headlines, images and, where available, search themes and audience signals. Signals guide the algorithm. They don't restrict it.
5. Clean conversion data
Count one primary purchase conversion, not several. Use server-side tracking and enhanced conversions so fewer sales are lost to browsers and consent. We treat measurement as infrastructure: tracking is fixed before we scale anything. See our guide to server-side tracking and enhanced conversions.
6. Bid to profit, not just ROAS
PMax optimises to the conversion value you send. Send revenue and it maximises revenue. Send gross profit and Target ROAS effectively becomes Target POAS. Where profit data isn't available yet, set separate targets per margin segment. Full method in POAS vs ROAS.
Settings worth checking in every Performance Max campaign
- Final URL expansion. Decide on purpose whether PMax may send traffic to pages other than the product page. For most shops, product traffic should land on product pages.
- Auto-apply recommendations. Review them before they change your account. For Hundlands we switched them off at takeover.
- New customer acquisition. If you use it, make sure customer lists are accurate, or you'll pay a premium for returning customers.
- Location targeting. Target people in your markets, not people "interested in" them.
- Asset quality. Low-quality or missing images and videos give Google less to work with. If you don't supply video, Google may generate it.
Performance Max vs Standard Shopping: a practical split
| Performance Max | Standard Shopping | |
|---|---|---|
| Channels | Search, Shopping, YouTube, Display, Discover, Gmail, Maps | Shopping only |
| Control | Lower; Google allocates across channels | Higher; you control bids and queries |
| Best for | Scaling proven products | Testing, tight control, low-data segments |
| Reporting | Less granular | Search terms and product data |
| Brand risk | Needs brand exclusions | Easier to exclude with negatives |
What good looks like
Accent Clothing is a good example of what changes when you stop letting PMax decide. We moved away from brand structure and focused on individual product performance, profit margins and competitive pricing, building campaigns around top-performing products across brands. ROAS went from 1.95 to 8.37 in five months, and up to 51% of misallocated ad spend was recovered. Read the Accent case study.
The lesson isn't "turn off Performance Max". It's control what deserves budget.
How to scale Performance Max
- Agree a target from your margins, not from a benchmark.
- Raise budget step by step while results beat the target.
- Pull back the moment they don't.
- Don't change budget, target and structure in the same week.
- Report brand and non-brand separately so you know what PMax really adds.
Our Octopus AI works the same way: it scores every product daily, cuts what spends without selling, and raises budget only while results beat your target, with a specialist watching every account.
The bottom line
Performance Max is powerful for e-commerce, but only as part of a structure. Exclude brand, segment by margin and performance, keep markets separate, fix tracking first and bid to profit where you can. Then let PMax do what it does best: scale the products that actually make money.
Running Performance Max and not sure what it's really adding? Get your free Google Ads audit.
FAQ
Is Performance Max good for e-commerce?
Yes, when it gets a clean feed, reliable conversion data and clear boundaries. Without those, it tends to spend on brand searches and a handful of best-sellers while the rest of the catalogue gets little budget.
Should I run Performance Max or Standard Shopping?
Often both. Performance Max is strong for scale across Google's channels. Standard Shopping gives more control and transparency. Many accounts run Performance Max for proven products and Standard Shopping for testing or tightly controlled segments.
Does Performance Max cannibalise brand searches?
It can. Performance Max can serve on your brand searches, which makes its ROAS look better than the new demand it creates. Use brand exclusions and keep brand traffic in a separate Search campaign.
How many Performance Max campaigns should an e-commerce brand have?
As few as needed to give each product segment its own target and enough conversion data. Usually one campaign per meaningful margin or performance segment per market, not one per category.
What ROAS target should I use in Performance Max?
Start from your break-even ROAS (1 ÷ gross margin) and set targets per segment based on margin. Where possible, send profit instead of revenue as conversion value so the campaign optimises to profit.
How long does Performance Max take to learn?
Expect a learning period after launch and after major changes. Avoid changing targets, budgets and structure at the same time. Structural fixes usually show within 30 to 60 days; profitable scaling is a 3 to 6 month project.
Sources
- Google Ads Help: About Performance Max campaigns
- Google Ads Help: About Target ROAS bidding