Performance Max Setup for Ecommerce: Feed-First Guide (2026)

Performance Max (PMax) is the Google Ads campaign type that serves ads across Search, Shopping, YouTube, Display, Discover, Gmail and Maps from a single campaign. For an online store, the real fuel is not your headlines or banners but the product feed in Google Merchant Center. This guide walks through a feed-first setup, from the decisions you make before you click "New campaign" to what you should and shouldn't touch during the learning period. Menu names are accurate as of September 2026; Google renames things often, so expect small differences.

What do you need before setting up Performance Max?

You need three things: a Merchant Center account with mostly approved products, that account linked to Google Ads, and a purchase conversion that fires once with the correct value. Without them, the campaign either can't serve Shopping ads or learns from the wrong signal.

PMax bids entirely on conversion data. If the purchase tag fires twice, "Add to cart" is set as a primary conversion, or order values mix in tax and shipping inconsistently, the algorithm optimizes toward the wrong target. On the product side, feed quality is ad quality: the cleaner your titles, images, prices and categories, the better your products match real searches. Fix disapprovals first; our guide to Merchant Center product disapprovals covers the most common causes.

• Merchant Center is linked to Google Ads and most products show as "Approved"
• Purchase is the only primary conversion action and it sends a transaction value
• Product titles follow brand + product type + key attributes (color, size, material)
• At least one of custom_label_0 to custom_label_4 is reserved for margin or performance tiers
• You can compare Google Ads, GA4 and store orders over the same date range

Feed-only PMax or a full-asset campaign?

A feed-only PMax campaign runs on the product feed alone, with no headlines, descriptions, images or videos in the asset group, so spend leans heavily toward Shopping ads. A full-asset campaign supplies text, images and video so Google can build ads for every channel.

Search Engine Journal's feed-only walkthrough leaves every asset field blank except business name and call to action, and turns off both Final URL expansion and automatically created assets. It also makes an important point: because Google now builds YouTube and Display ads from feed images, feed-only is "Shopping-dominant" rather than strictly Shopping-only. Google's own optimization tips point the other way: aim for at least 15 headlines, 5 descriptions, 7 images (3 landscape, 3 square, 1 portrait) and at least one video per asset group.

A simple decision rule: if you have no creative capacity and the goal is direct product sales, start feed-only. If you can produce images and video, go full-asset, but watch the channel split from the first week. If you want to know when classic Standard Shopping still wins, read our Shopping vs Performance Max comparison.

How do you set up a Performance Max campaign step by step?

Setup has five stages: objective, feed, budget and bidding, campaign settings, and the asset group. The order below follows the English Google Ads interface.

1. Objective and type Go to Campaigns, click the plus button, choose the Sales objective and select Performance Max as the campaign type.
2. Link the feed Pick your Merchant Center account and which products to include: all of them, or only those with a specific feed label (feed labels have replaced country of sale for product selection). Without a feed, the campaign can't show Shopping ads.
3. Budget and bidding Set bidding to focus on conversion value. With little conversion history, many advertisers launch without a target ROAS and add one once data builds up.
4. Campaign settings Under location options choose "Presence: People in or regularly in your targeted locations", then set brand exclusions and your Final URL expansion preference.
5. Asset group Define product coverage with listing groups, add assets (or not, for feed-only), audience signals and search themes, then publish.

How should you split Performance Max asset groups?

An asset group combines a set of products with the creative and signals that go with them. Google recommends splitting asset groups by content category, theme, language or audience; for ecommerce, the two most useful axes are product category and margin.

Splitting by category keeps creative relevant: a "Women's boots" group should never show a men's watch image. Splitting by margin is about bidding, and here is the catch most guides skip: target ROAS is set at the campaign level. If high-margin and low-margin products need different ROAS targets, they have to live in separate campaigns, not separate asset groups in one campaign. Asset groups separate creative and reporting; they don't separate bids.

Worked example: splitting by margin

Break-even ROAS is 1 ÷ gross margin. A product with a 50% margin breaks even at a ROAS of 2 (200%); a product with a 25% margin needs 4 (400%). Manage both under one 350% target and the algorithm underbids on the high-margin items while the low-margin ones can lose money on every sale. Find your own thresholds with the break-even ROAS calculator.

In practice, splitting too finely spreads conversion data thin and slows learning. For most small and mid-sized stores, two or three campaigns with a handful of category asset groups each is enough.

How do listing groups control which products show?

Listing groups are the filters that decide which products an asset group can advertise. According to Google Ads Help, you can subdivide by category, brand, item ID, condition, product type, channel and up to five custom labels.

The path is Campaigns, then your Performance Max campaign, then Asset groups, then the Listing groups tab. Each asset group can hold up to 1,000 listing groups, but Google states that such a large number is not best practice and can hurt performance; it recommends grouping items with custom labels and targeting those labels instead. Subdividing by Google product category only works when you target a short list of countries: the US, the UK, Australia, Germany, France, Japan, Italy, the Netherlands, Brazil, Norway, Sweden and Turkey. Elsewhere, use product type and custom labels.

What do audience signals and search themes actually do?

Audience signals and search themes are hints, not targeting. You tell Google where to start, and the algorithm is free to go beyond them. Their main benefit is a shorter ramp-up.

Google suggests adding remarketing lists, custom segments and Customer Match lists as signals. For a store, the strongest signals are usually recent purchasers and cart abandoners. With search themes you can add up to 50 per asset group; fill them with phrases people actually use for that product group, such as "men's leather chelsea boots" or "waterproof hiking shoes". Leave your own brand name out of search themes.

Why do you need brand exclusions in Performance Max?

Brand exclusions stop PMax from showing ads to people already searching for your brand, who would likely buy anyway, and then claiming those sales. Without them, PMax ROAS often looks better than the incremental value it really adds.

When creating a campaign, you'll find it under More settings, then Brand exclusions; on an existing campaign it sits under Additional settings. Pick an existing brand list or create one. Google Ads Help says exclusions apply to Search, Shopping and YouTube search inventory, but not to Display. There's also an "Allow Shopping ads on searches that mention excluded brands" checkbox. If a separate Search campaign already covers branded queries, you can leave it unchecked. For query-level cleanup, Google's August 2025 update lets you apply negative keyword lists, which cover Search and Shopping inventory, to PMax campaigns and opened search terms reporting to every PMax campaign.

How long is the Performance Max learning period?

Google recommends running a new Performance Max campaign for at least six weeks before evaluating it, and allowing 1–2 weeks, or at least one full conversion cycle, after any major change. Frequent edits in that window reset learning and cause swings.

• Don't make big jumps in target ROAS or budget during the first two weeks; adjust in small steps if needed
• Wait 2–3 weeks after changing assets before replacing low performers
• Check the channel performance report weekly to catch spend drifting into YouTube or Display
• Review the search terms report and add irrelevant queries to a negative list
• Compare Google Ads conversions with real orders in your store admin

That last step is the one most stores skip. Google Ads, GA4 and your store platform use different attribution rules, so the numbers never match exactly; what matters is that the gap stays reasonable and stable. Instead of rebuilding that comparison by hand every week, you can track all platforms side by side in Marpany's ad performance dashboard. For a broader optimization framework, start with our Google Ads optimization guide.

Next steps: your first 30 days

The goal of month one is clean data, a clean feed, and tightening target ROAS only after enough conversions have come in.

1. Week 1: Check Merchant Center diagnostics for new disapprovals and warnings, and confirm conversions arrive with correct values.
2. Week 2: Review the search terms and channel performance reports; add irrelevant queries to your negative list.
3. Week 3: Find products that spend without selling at listing group level and move them into their own custom label group.
4. Week 4: Compare actual ROAS with your break-even ROAS and adjust the target in small steps; in full-asset campaigns, swap out low-rated assets.