Google Ads
Performance Max for ecommerce stores
Performance Max (PMax) is a Google Ads campaign type that runs one campaign across all of Google's ad inventory, with automation choosing placements and bids. For online stores, it's driven largely by your Merchant Center product feed. It optimizes toward whatever value you report, so if you report revenue, it chases revenue, not profit.
How Performance Max works
According to Google's Performance Max help, it's "a goal-based campaign type that allows you to access all Google Ads inventory" from one campaign. That includes YouTube, Display, Search, Discover, Gmail and Maps.
A campaign is built from:
- Your goal and bid strategy, such as maximizing conversion value with a target ROAS.
- Asset groups: collections of images, text, logos and videos, grouped by theme or audience. For retail, an asset group is also tied to a set of products from your feed.
- Your product feed from Merchant Center, which supplies products, prices and images for Shopping-style ads.
- Audience signals: hints such as your customer lists or interests that help Google learn faster. They're signals, not strict targeting.
Google's automation then decides, for each auction, which channel, which ad format and which bid to use.
Feed-led vs full-asset PMax
Stores often compare two ways of setting up PMax:
| Feed-led | Full asset | |
|---|---|---|
| What you provide | Mainly the product feed, with minimal creative | Feed plus a full set of images, headlines, descriptions and videos |
| Where ads tend to run | Mostly Shopping-style product ads | Across product, display and video formats |
| Best for | Stores wanting PMax to behave close to Shopping | Stores with strong creative wanting reach beyond Search |
| Watch out for | Less reach on video and display | Budget drifting into channels that convert poorly |
Google's asset requirements change over time, so check what each asset group currently needs when you build one. Whichever setup you use, look at channel-level reporting to see where spend actually goes.
Controls available
Google lists these controls for Performance Max:
- Negative keywords, to keep ads off irrelevant searches.
- Brand exclusions, to stop PMax spending on searches for your own brand or others.
- Search themes, to steer which searches it considers.
- Final URL expansion settings, controlling whether Google can send traffic to other pages on your site.
- Channel and asset reporting, to see performance by channel and by creative.
Measuring profit, not ROAS
PMax maximizes the conversion value you report. If that value is revenue:
- It will happily sell low-margin products at the same ROAS as high-margin ones, so some sales lose money.
- It can take credit for brand searches that would have converted anyway.
- Its ROAS can look strong while profit after ad spend is thin.
To keep it honest:
- Set targets from your margin. Break-even ROAS = 1 ÷ gross margin. See the guide to ROAS.
- Split products by margin into separate campaigns or asset groups, each with its own target.
- Consider reporting profit-based conversion values, so the algorithm optimizes toward profit, not revenue.
- Exclude your brand if you run separate brand search campaigns, so you can see PMax's real contribution.
- Track new vs returning customers. A campaign that mostly re-sells to existing customers is worth less than it looks. The CAC payback calculator helps judge what new customers are worth.
Before you launch PMax
- Fix your feed first: clean titles, correct prices, real GTINs. See the Merchant Center guide.
- Make sure conversion tracking is accurate, including order values.
- Start with your profitable products, not the whole catalog.
For Google's other automated, visual campaign type, see Demand Gen campaigns.
FAQ
What is PMax?
Performance Max (PMax) is a Google Ads campaign type that runs one campaign across all of Google's ad inventory, with Google's automation choosing where to show ads and how much to bid to reach your goal.
Where do Performance Max ads show?
According to Google, across YouTube, Display, Search, Discover, Gmail and Maps.
Does Performance Max replace Shopping campaigns?
Not entirely. Standard Shopping campaigns still exist, and some stores run both. PMax reaches more placements; standard Shopping gives more manual control over product-level bids.
Can I control where my PMax ads show?
Partly. Google provides controls including negative keywords, brand exclusions and search themes, plus channel-level and asset-level reporting. You can't pick placements one by one.
Why is my PMax ROAS high but profit low?
PMax optimizes toward the conversion value you report. If you report revenue, it chases revenue, including low-margin products and brand searches you'd have won anyway. Feed it profit-aware values and judge it on profit.