Google Shopping for ecommerce works by turning your product feed into ads that show an image, price and shop name before anyone clicks. In 2026 you can run those ads through Standard Shopping campaigns, which give you tight control, or Performance Max, which uses the same feed across every Google channel and lets Google's bidding decide where to spend. For many UK brands, the strongest setup is Performance Max for ecommerce as the main engine, with Standard Shopping kept for situations where control matters more than reach.
Neither campaign type will fix a weak feed, poor tracking or the wrong targets. This guide covers how both work today, when to use each, and what actually moves return on ad spend.
How Does Google Shopping Work for Ecommerce in 2026?
Every Shopping ad starts in Google Merchant Center. You upload a product feed, Google checks it against its product data specification, and approved products become eligible to show. You never write keywords for Shopping. Google matches searches to products using your titles, descriptions, categories and attributes.
That is why the feed is the account: it decides which searches you are eligible for.
You then choose how to advertise those products:
- Standard Shopping: Shopping ads only, on Google Search, the Shopping tab and partner sites. You set the bidding, split products into product groups and add negative keywords directly.
- Performance Max: one campaign that can serve across Search, Shopping, YouTube, Display, Discover, Gmail and Maps, using your feed plus any text, image and video assets you supply. Bidding is fully automated towards a conversion value or ROAS goal.
How Does Performance Max Work for Ecommerce?
A Performance Max campaign is built from asset groups. Each asset group holds creative (headlines, descriptions, images, videos), optional audience signals and search themes, and a set of products chosen through listing groups. Listing groups let you include or exclude products by brand, category, product type, item ID or custom label.
The controls advertisers asked for have improved a lot. Google now offers:
- Search themes: phrases that tell Google which searches you want to be considered for. Search themes are signals, not keywords, so treat them as guidance rather than hard targeting.
- Brand exclusions: lists that stop your campaign showing on searches for named brands, including your own. Google explains how to set them up in its brand exclusions guide.
- Campaign-level negative keywords: rolled out to all advertisers in 2025, alongside asset group segmenting and downloadable asset reports, as set out in Google's 2025 Performance Max update.
- Search terms report: you can see the actual queries your ads matched, covered in Google's search terms report for Performance Max.
- Channel performance report: a breakdown of results by Search, YouTube, Display, Discover, Gmail, Maps and Search partners, filterable by ads using product data or video. See Google's channel performance report help page.
Channel reporting shows whether your money is going to product ads on Search or being spread thinly across placements that rarely convert.
Standard Shopping vs Performance Max: Which Should You Use?
The standard Shopping vs Performance Max question has no single answer. It depends on your conversion volume, margins and how much control you need.
Performance Max is usually the right primary campaign when:
- You have steady purchase volume, so automated bidding has enough data to learn from.
- Your conversion tracking passes accurate order values.
- You can supply decent creative, or are happy for the campaign to run mainly on product ads at first.
- You want reach beyond Search, including YouTube and Discover.
Standard Shopping still earns its place when:
- You need to test a new range, market or pricing without the campaign drifting into other channels.
- Conversion volume is too low for automated bidding to work well.
- You need very precise control over specific products or search terms.
Overlap is handled by the auction. Google says that when campaigns could serve the same impression, it prioritises the campaign with the highest Ad Rank. Performance Max no longer automatically wins over Standard Shopping, so running both on the same products needs a clear reason and careful reporting.
What Makes a Good Product Feed in Merchant Center?
Product feed optimisation is the highest-return work in most Shopping accounts. Google's product data specification sets the rules. Getting above the minimum is where the gains are.
- Titles: put the words shoppers search first. Brand, product type and the key attributes (size, colour, material, model) usually beat marketing names. A title of "Linen Shirt, Men's, Slim Fit, Navy" will match more searches than "The Riviera".
- Images: clean, well-lit, product-focused main images with no promotional overlays or watermarks. Add extra images through the additional image link attribute.
- GTINs: submit the correct GTIN for every branded product that has one. It helps Google match your listing to the exact product people search for.
- Attributes: fill in google_product_category, product_type, brand, colour, size, gender, age group and material where relevant. Missing attributes mean missed searches.
- Price and availability: keep these in sync with your site. Mismatches cause disapprovals and lose shopper trust.
- Custom labels: use custom_label_0 to 4 for business data Google cannot see, such as margin band, best seller status, season or clearance.
Check the Merchant Center diagnostics weekly. Disapproved and limited products are revenue you are not even competing for. Google lists common problems in its guide to fixing product data quality disapprovals.
If your feed comes from Shopify, the platform setup matters as much as the ads. Our ecommerce marketing and Shopify team often fixes feed structure at source so it stays fixed.
How Should You Structure Campaigns by Margin and Best Sellers?
Google bids towards revenue. Your business runs on profit. A £100 sale at 15% margin and a £100 sale at 60% margin look the same to the algorithm unless you tell it otherwise.
A practical structure for most UK ecommerce brands:
- Group by margin band: tag products high, medium or low margin with a custom label, then split them into separate campaigns or asset groups with different ROAS targets.
- Protect best sellers: give proven products their own campaign or asset group so budget is not diluted by hundreds of low-volume items.
- Isolate zombie products: products with impressions but few clicks, or no impressions at all, often need better titles or a separate test campaign with its own budget.
- Separate seasonal and clearance stock: these need different targets.
Keep the structure simple enough that each campaign still gets enough conversions to learn. Splitting too finely starves automated bidding of data.
How Do You Set ROAS Targets and New Customer Goals?
Your target ROAS should come from your numbers, not an industry average. Start with break-even ROAS: if your gross margin after fulfilment costs is 40%, you need roughly £2.50 in revenue for every £1 of ad spend just to break even. Set targets from there, depending on whether the goal is profit now or growth.
Change targets gradually. Large swings unsettle automated bidding and make results hard to read.
Performance Max also has a new customer acquisition goal with two modes:
- Bid higher for new customers: the campaign still sells to returning customers but values new ones more.
- Bid for new customers only: useful when you have a strict acquisition budget and serve existing customers elsewhere.
Both depend on Google knowing who your existing customers are, so you need to upload customer lists or use your website tag. Brands with strong repeat purchase rates benefit most, because Google is otherwise rewarded for selling to people who would have bought anyway.
How Should You Measure Shopping and Performance Max?
Automated bidding is only as good as the data you feed it. Before scaling spend, check:
- Purchase conversions pass the real order value, ideally excluding VAT and shipping so ROAS reflects revenue you keep.
- Only purchases are primary conversions. Add to basket and page views as primary goals will teach the campaign to chase the wrong thing.
- Enhanced conversions are set up to improve match rates. Google's enhanced conversions documentation covers the options.
- Consent mode is working for UK and EU visitors, so you are not losing conversion data unnecessarily.
- Google Ads and your store platform broadly agree on order numbers. If they do not, fix tracking before touching bids.
Then look beyond platform ROAS. Compare total revenue, new customer revenue and contribution margin over time. Our tracking and analytics team builds this reporting so decisions are based on profit, not just what Google Ads reports.
What Are the Most Common Shopping and PMax Mistakes?
- Letting brand searches inflate ROAS: without brand exclusions, Performance Max can take credit for people already searching for you.
- Putting the whole catalogue in one asset group: budget flows to a handful of products and the rest never get tested.
- Ignoring the feed: spending hours on bids while titles and attributes stay thin.
- Judging too early: changing targets or structure every few days before the campaign has enough data.
- Weak creative: low-quality images or no video limits how well Performance Max performs outside Shopping placements.
- Ignoring the landing page: slow product pages, poor mobile layouts and unclear delivery costs kill conversion rates. That is a conversion rate optimisation job, not a bidding one.
What Should a Google Shopping Agency Do for You?
A good Google Shopping agency should spend as much time on your feed, tracking and margins as on the campaigns themselves. As a minimum, expect:
- A feed and Merchant Center audit, with title, attribute and GTIN fixes prioritised by revenue impact.
- Conversion tracking checked and fixed before budgets increase.
- A campaign structure based on your margins and best sellers.
- ROAS targets agreed from your break-even point, not a generic number.
- Regular reviews of search terms, channel performance and brand exclusions.
- Clear reporting on revenue, new customers and profit.
Kinsman & Co is a London-based Google Partner working with ecommerce, hospitality, B2B and lead generation brands. If you are comparing an ecommerce PPC agency in London, our PPC agency services page sets out how we run Google Ads.
Frequently Asked Questions
1. Is Google Shopping the same as Performance Max?
A: No. Google Shopping refers to the product ads built from your Merchant Center feed. Performance Max is a campaign type that can show those Shopping ads plus ads across YouTube, Display, Discover, Gmail and Maps.
2. Do I still need Standard Shopping if I run Performance Max?
A: Not always. Many brands run Performance Max as their main campaign and use Standard Shopping for testing, low-volume products or situations where they need tight control.
3. What is a good ROAS for Google Shopping?
A: It depends on your margins. Work out your break-even ROAS first, then set a target that delivers the profit or growth you need. An average from another business tells you very little about yours.
4. How long does Performance Max take to settle?
A: There is no fixed period. It depends on conversion volume and how much you change. Give the campaign enough conversions to learn before judging it, and avoid big target changes in the meantime.
If your Shopping or Performance Max campaigns are spending but not delivering profitable growth, the issue is usually in the feed, tracking or structure. Book a call with Kinsman & Co and we will review your Google Ads and Merchant Center setup and show you where the gains are.
