What is Performance Max for ecommerce, and should an established brand use it?
Performance Max for ecommerce is a goal-based Google Ads campaign that runs on your Merchant Center product feed and creative assets, and reaches all Google Ads inventory, including Search, YouTube, Display, Discover, Gmail and Maps, from one campaign. An established brand should use it when it is judged on new-customer revenue, not on the return it reports.
The campaign decides where each pound goes. For a brand selling £100k or more a month, much of the demand already exists: people searching your brand name and past customers coming back. Performance Max is very good at winning those conversions because they are cheap to win. When we inherit a Google Ads account, the useful question is how much of what PMax reports would have happened anyway, and how much budget is left for people who have never bought from you.
How does Performance Max differ from Standard Shopping?
The difference between Performance Max and Standard Shopping is control against reach. Standard Shopping serves Shopping ads only, lets you bid on product groups you define, and shows you the search terms behind your clicks. Performance Max adds every other Google channel and hands most placement and bidding decisions to Google's automation.
When both campaigns are eligible for the same auction, Google says the campaign with the highest Ad Rank serves. Performance Max does not win by default, so running both in one account is a workable structure rather than a conflict.
| Question | Performance Max | Standard Shopping |
|---|---|---|
| Where ads can show | All Google Ads inventory from one campaign | Shopping ads only |
| What you control | Asset groups, listing groups, audience signals, exclusions | Product groups, bids, negatives, campaign structure |
| What you can see | Search terms, channel and asset reports, with less detail per click | Search terms and product-level data |
| Best job | Reaching new demand across channels | Capturing known product searches at a controlled cost |
Where does Performance Max quietly buy branded and returning-customer sales?
Performance Max optimises towards the conversions it can win most cheaply. For an established brand those are usually branded searches and existing customers, both of whom were likely to buy anyway. The campaign reports a strong return and gets more budget, while total revenue barely moves. A common picture in a new account is a PMax campaign that looks like the best performer on the dashboard while new-customer numbers stay flat.
None of this is Google misbehaving. The campaign is doing what it was asked: find conversions at a target return. If the goal does not separate new from returning buyers, or brand from non-brand, the cheapest path wins. These are the signs we look for first:
- Brand terms in the search terms report: a large share of PMax conversions coming from your own name or product names.
- Flat blended return: PMax ROAS climbing while total revenue divided by total marketing spend does not.
- Returning-customer skew: most PMax purchases coming from people already on your customer list.
- Branded Search shrinking: your brand campaign losing impressions as PMax spend rises.
Why is the Google Shopping feed the real lever in PMax?
The Google Shopping feed is what Performance Max reads to decide which product to show for which search. A weak feed gives the automation weak inputs, and no bidding setting fixes that. Google's product data specification allows titles of up to 150 characters that should clearly identify the product and match the landing page, and it states that providing the correct GTIN results in the best performance.
In the Shopify stores we audit, the feed is often whatever the default app pushed on day one: short titles, missing colour and size attributes, no GTINs and one generic product type. These are the fixes we make before touching bids:
- Titles: lead with the brand and product name, then the attribute people search for, such as size, flavour or material.
- GTINs: submit valid codes for every product that has one.
- Product type: build a clear hierarchy, because Google uses the first value to organise bidding and reporting.
- Images: clean product shots that match the variant being sold.
- Disapprovals: clear them weekly, not quarterly.
How should you split asset groups and listing groups by margin?
Asset groups and listing groups should follow profit, not the Shopify collection menu. A single asset group holding every product lets Google push whatever converts most easily, which is often your lowest-margin bestseller. Splitting by margin lets you set different return targets for products that can afford different acquisition costs.
Merchant Center gives you five custom labels, numbered 0 to 4, each up to 100 characters, and Google's own examples include margin, seasonality, selling rate and price range. We usually structure it like this:
- Tag each product in the feed with a margin band in custom_label_0.
- Use custom_label_1 for hero, core, long tail or clearance status.
- Build separate campaigns or asset groups for high-margin and low-margin products, each with its own return target.
- Write asset group creative for the product theme, not the whole catalogue.
- Review the bands monthly as costs and prices change.
How do brand exclusions and negative keywords work in Performance Max?
Brand exclusions are Google's main tool for keeping Performance Max off your own brand searches. They block ads on searches for your brand name, including common misspellings and related subsidiary brands. They apply to Search and Shopping inventory within PMax. When you apply them, there is a setting to allow Shopping ads on searches that mention excluded brands, which is useful if you want product ads to keep showing while a dedicated brand Search campaign takes the text ads.
Negative keywords now work in Performance Max at campaign and account level, and apply to Search and Shopping inventory only. In August 2025 Google announced campaign-level negative keyword lists, search terms reporting for all Performance Max campaigns, device targeting controls and 50 search themes per asset group, up from 25. The channel performance report shows how results split across Search, YouTube, Display, Discover, Maps, Gmail and Search partners. Read it before deciding whether the campaign is doing prospecting or recapture.
Should you use the new customer acquisition goal?
The customer acquisition goal is the most direct way to stop Performance Max favouring people who already buy from you. Google's customer lifecycle goals offer two modes. New Customer Value bids higher for new customers while still reaching returning ones. New Customer Only bids exclusively for new customers. Both need a purchase conversion goal, and New Customer Value needs a value-based strategy such as Target ROAS or Maximise conversion value.
The goal only works if Google can tell who your existing customers are. That means uploading a customer list from Shopify or Klaviyo and keeping it current, alongside your website tag. We usually start with New Customer Value and a realistic value per new customer based on first-order margin and repeat behaviour, then test New Customer Only on high-margin products where the numbers support it. An out-of-date list quietly turns the goal back into a returning-customer campaign.
How do you judge whether Performance Max is working?
Judge Performance Max by what it adds to the business, not by the ROAS in its own report. That report counts every conversion the campaign touched, including branded and repeat buyers who were on their way already. The two numbers that matter are blended return, meaning total revenue divided by total marketing spend, and new-customer revenue over the same period. We set out why we track one number elsewhere, and how we measure client results.
If you are unsure, test it. Google offers a Standard Shopping versus Performance Max experiment with a traffic split, and if you set an end date, Google fills in 12 weeks from the start. Before and during any test, we track these:
- Blended return across all paid channels, week by week.
- New-customer revenue and new-customer count from Shopify.
- Share of PMax conversions from brand search terms.
- Branded Search impression share before and after changes.
When should you run Performance Max, Standard Shopping, or both?
The right setup depends on how good your inputs are and whether you can measure new customers. This is the decision table we use when taking over a Google account.
| Your situation | What we would run | Why |
|---|---|---|
| Clean feed and customer list uploaded | Performance Max with brand exclusions and the new customer goal | The automation has good inputs and a clear definition of success |
| Weak feed or no customer list yet | Standard Shopping while the feed is fixed | You keep control and search term visibility while the inputs improve |
| Large catalogue with mixed margins | Both: PMax on high-margin groups, Standard Shopping on the rest | Different products justify different acquisition costs |
| Heavy branded demand | Branded Search, plus PMax with brand exclusions | Stops PMax claiming sales your brand already earned |
| Low conversion volume | Standard Shopping first | Automation needs enough purchases to learn from |
| Peak trading such as Black Friday | Existing structure, no rebuilds | Learning periods and peak trading do not mix |
For the peak season point, our Black Friday planning guide covers how to ramp budgets and load creative before the peak.
Where RedPxl fits
Our paid media team runs Google Shopping and Performance Max for ecommerce brands selling £100k or more a month, with feed work and creative handled in the same team. Every account has one named specialist, and every budget change is explained in writing. If PMax looks strong in the dashboard but total revenue is not moving, tell us what you are working with.
Questions we get asked
- Does Performance Max replace Standard Shopping?
- No. Both campaign types still exist and can run in the same account. When both are eligible for the same auction, the campaign with the higher Ad Rank serves. Many established brands run both, using Standard Shopping where they want search term control and Performance Max where they want reach beyond Shopping.
- How long should a Performance Max campaign run before you judge it?
- Give it long enough to exit learning and collect a meaningful number of purchases, which for most brands means several weeks rather than days. Google's own Standard Shopping versus Performance Max experiment suggests 12 weeks if you set an end date. Avoid major changes to goals or budgets during that window, or the comparison stops being clean.
- Can you see search terms in Performance Max?
- Yes. Google made search terms reporting available for all Performance Max campaigns and through the API in 2025. The report shows the search terms that triggered your ads, with the landing pages and ad formats involved. Use it to find brand terms and irrelevant queries, then add brand exclusions or negative keywords.
- What budget does Performance Max need for an ecommerce brand?
- There is no fixed minimum, but the campaign needs enough daily budget to generate regular purchases at your target return, otherwise bidding has too little data to learn from. Splitting a small budget across many asset groups makes this worse. Start with fewer, margin-based groups and expand once each one converts consistently.
