Google Performance Max for Shopify: Structure, Feeds and Exclusions That Work

Performance Max works well for Shopify stores when you give it a clean product feed, a simple structure based on margin and priority, and clear exclusions. Keep branded search in its own Search campaign, exclude your brand from PMax, add negative keywords for irrelevant queries, and check the channel and search terms reports every week.

In short:

• Your Merchant Center feed is the foundation. Fix titles, images, prices and identifiers before tuning bids.
• Group products by margin and priority with custom labels, then build one to three PMax campaigns around them.
• Use brand exclusions and campaign-level negative keywords to stop PMax taking credit for demand it did not create.
• Use the new customer acquisition goal if growth, not repeat orders, is the priority.

How Performance Max works for a Shopify store

Performance Max is a goal-based campaign that can show ads across YouTube, Display, Search, Discover, Gmail and Maps from a single campaign. For ecommerce, it also serves Shopping ads using your product feed from Google Merchant Center.

That means two inputs drive most results: the feed (what products exist, at what price, with what titles and images) and the conversion data (which clicks turned into purchases). On Shopify, both usually come from the Google & YouTube app, which syncs products to Merchant Center and sets up purchase tracking.

Step 1: Fix the feed before anything else

Google matches Shopping ads to searches largely through your product data. A weak feed limits what even a perfect campaign can do.

Use custom labels for margin and priority

Custom labels (custom_label_0 to custom_label_4) let you tag products with information Google does not have, such as margin tier, bestseller status or season. If the Shopify app does not let you set them easily, add them through a supplemental feed in Merchant Center, for example a Google Sheet keyed by product ID.

A simple scheme for a D2C store:

• custom_label_0: margin tier (high, medium, low)
• custom_label_1: hero, core or long tail
• custom_label_2: season or festive collection

Step 2: Choose a structure that matches your data

The biggest mistake is building one PMax campaign per collection. Each campaign then gets too few conversions to learn. Match the number of campaigns to your conversion volume.

These thresholds are rules of thumb, not Google requirements. The principle is to split only when each campaign will still have steady conversion volume.

Asset groups

Inside each campaign, build asset groups by theme, such as men's shirts and women's dresses, with matching listing groups, images, videos and headlines. Google now allows up to 50 search themes per asset group, according to Google Ads Help. Use them to signal the searches you care about, like "linen shirts for summer", not as a keyword list.

Add audience signals from your customer list and site visitors. They guide early learning but do not restrict who sees the ads.

Step 3: Set exclusions and controls

Google has added more controls to PMax over the last year. These are the ones worth using on a Shopify account:

• Brand exclusions: build a brand list and apply it to PMax. Per Google Ads Help, brand exclusions apply to Search, Shopping and YouTube search inventory, with an option to still let Shopping ads appear on excluded brand searches. Run brand terms in a separate Search campaign.
• Negative keywords: Performance Max supports campaign-level negative keywords, now up to 10,000 per campaign, plus negative keyword lists. They apply to Search and Shopping inventory. Start with obvious irrelevant terms, such as "free", "jobs", "wholesale" or "DIY", then add more from the search terms report.
• Final URL expansion: if Google sends traffic to pages that do not sell, such as blog posts or policy pages, exclude those URLs or turn expansion off. You can now see and remove final URL expansion assets.
• Device and age controls: Google has introduced device targeting and age-based demographic controls in PMax. Use them only when your data clearly supports it.

Step 4: Pick the right goal and bidding

For most Shopify stores, start with Maximise conversion value without a target for the first few weeks, then add a target ROAS once you have stable data. Set it near what the campaign is already achieving, then tighten gradually.

If you want PMax to focus on first-time buyers, use the new customer acquisition goal. It relies on your customer lists and Google tag to identify existing customers, and can either bid only for new customers or bid higher for them. Google has also added a column for new customer acquisition cost reporting.

Step 5: Review the reports weekly

• Channel performance report: now available in all PMax campaigns, it shows how Search, Shopping, YouTube, Display and other channels contribute. If most spend goes to Display with few conversions, look at your assets and URL expansion.
• Search terms report: available for all PMax campaigns. Use it to find negative keywords and new search themes.
• Asset reporting: full asset stats now show conversions, cost and clicks per asset. Replace clear underperformers.
• Merchant Center diagnostics: check for disapproved or limited products every week.

Common PMax mistakes on Shopify

• Running PMax with the Google & YouTube app's purchase action and an older manual gtag purchase action both set as primary, which double counts revenue.
• Letting PMax bid on your brand name, then reading its ROAS as proof of new demand.
• Changing ROAS targets every few days, which resets learning.
• Ignoring Merchant Center warnings until half the catalog is limited or disapproved.
• Uploading only feed products with no images or video, then wondering why YouTube and Display placements underperform.

A worked example

Here is an illustrative case to show the logic. A home-décor store has 400 products, but 60 of them drive most sales and carry the best margins. It tags those 60 as "hero" with a custom label, then builds a PMax campaign for heroes with a moderate ROAS target, a second campaign for the remaining products with a higher target, and a brand Search campaign. Brand exclusions keep PMax off brand queries. After three weeks, the search terms report shows spend on "wall art free download", which it adds as a negative keyword.

Landing pages matter too. If PMax sends traffic to a product page that loads slowly or buries the price, conversion rates suffer. Our product page teardown covers what to fix.

Get PMax structured properly

Performance Max rewards clean data and punishes messy accounts. If you want help with feed optimisation, campaign structure and weekly reviews, our Google Ads team can audit your current setup and rebuild it around your margins.