Product Feed Optimisation: The Hidden Lever in Shopping Ads

Why the feed outweighs your bidding strategy

Google Shopping campaigns have no keywords. Whether you run Standard Shopping or Performance Max, Google decides which searches your products appear for by reading your product feed: the structured file of titles, descriptions, identifiers and attributes sitting in Google Merchant Center. If that file is thin or messy, no amount of bid tweaking can compensate, because Google simply does not know when your products are relevant.

Most UK stores set the feed up once through a Shopify app or WooCommerce plugin and never look at it again. Those default exports are built for convenience, not performance: titles come straight from the website, colours and sizes hide in variant fields Google barely reads, and half the catalogue shares one generic category. That gap is why feed work is usually the cheapest performance gain available in Shopping, and why two stores paying identical costs per click can see wildly different results.

Titles: the highest-impact field you control

Google weighs titles more heavily than any other feed attribute when matching queries, and shoppers scan them to decide whether to click. Yet default titles are written for site navigation, not search. "Aria Midi Dress" tells Google almost nothing; "Floral Midi Wrap Dress, Green, Sizes 8 to 18" can match dozens of real queries. Google accepts up to 150 characters, but most placements truncate at around 70, so front-load the words people actually type.

Title structures that work by category

• Apparel: brand, gender, product type, colour, size. Example: "Organic Cotton Men's Crew Neck T-Shirt, Navy, S to XXL"
• Hard goods: brand, model, product type, key spec. Example: "Bosch 18V Cordless Combi Drill with 2 Batteries"
• Consumables: brand, product type, variant, weight or count. Example: "Peppermint Loose Leaf Tea, 250g Pouch"
• Gifting and seasonal lines: include the use case people search for, such as "Personalised Whisky Glass, Engraved Gift for Him"

Rewrite your top 50 revenue products by hand first. The long tail can be improved in bulk with rules, which we cover below.

Identifiers: GTINs, brand and MPN

The GTIN, in the UK usually the EAN barcode number, matches your product to Google's own catalogue. A correct GTIN improves query matching because Google already understands what the product is, makes you eligible for more surfaces including comparison views, and generally lifts the whole listing. A missing or wrong GTIN drags performance and can trigger disapprovals.

• Reselling branded goods: request EANs from your supplier or distributor. Never guess or copy a similar product's code
• Own-brand products: if you bought GS1 barcodes for retail packaging, those numbers are your GTINs
• Genuinely bespoke or handmade items: set identifier_exists to false rather than inventing a number, which risks disapproval
• Always populate the brand field, and add the MPN wherever a manufacturer part number exists

Custom labels: segment before you spend

Custom labels 0 to 4 are five free-text fields that exist purely for your campaign structure. Google ignores them for matching, but you can use them to split the catalogue into groups with different targets. Without labels, Performance Max treats your entire range as one pot and quietly concentrates spend on whatever converts most easily, which is rarely what makes you the most money.

• Margin bands (high, mid, low), so thin-margin lines get a stricter return target
• Price bands, because items under £20 behave differently in auctions from items over £200
• Velocity: bestsellers versus long tail, so new products are not starved by proven winners
• Seasonality tags such as summer, christmas and evergreen, ready for ramp-ups
• Clearance stock you want gone at almost any acceptable return

Once labels exist, build campaigns or asset groups around them and set targets that reflect the economics of each group rather than a single blended number.

Supplemental feeds: change the data without touching the site

You should not rewrite your website product names to please an algorithm. A supplemental feed, often just a Google Sheet joined to your main feed by item ID, lets you override or add attributes for Google only. Merchant Center's built-in rules can also transform data automatically, such as appending colour and size to every title. The current Merchant Center interface files these under data sources and rules, but the principle is unchanged.

• Override titles for your best sellers with hand-written, search-led versions
• Add custom labels from a margin export out of your accounts package
• Fill in missing google_product_category values for stricter policy categories
• Push sale_price during promotions without touching theme code
• Exclude problem SKUs from Shopping while you fix their data

The practical benefit is speed: a spreadsheet-literate marketer can test a feed change in an afternoon, with no developer in the loop.

What improvement looks like in practice

Imagine a homeware store whose feed exports "Luna Vase – Small". After optimisation the title reads "Handmade Ceramic Bud Vase, Sage Green, 12cm". The mechanism of improvement is predictable: the product starts entering auctions for ceramic vase, bud vase and sage green decor searches it previously never matched; click-through rate rises because the title answers size and material questions before the click; and conversion holds up because visitors arrive better qualified.

Measure the effect where it shows: new query themes in your search terms insights, product-level click-through rate, and conversion value split by your custom labels. Give each change two to four weeks before judging it, because Shopping data is noisy at low volumes, and change one variable at a time on any product you are watching closely.

A monthly feed hygiene routine

• Check Merchant Center diagnostics for disapprovals and warnings, fixing the highest-traffic items first
• Resolve price and availability mismatches between feed and site, which quietly suppress listings
• Scan search terms for new query language and reflect it in titles
• Confirm promotions and sale prices have correct end dates
• Re-tag custom labels as margins, stock and bestsellers change
• Spot-check images against policy: clean backgrounds, no watermarks or promotional text overlays

Half a day a month keeps the feed compounding while competitors leave theirs on autopilot. If you would rather have a specialist manage titles, labels and supplemental feeds alongside your campaigns, our team at Thind Global Services can help.