Your product feed is the engine behind Shopping and Performance Max. Most stores leave it in a broken or default state and wonder why bids and budgets are not working. Here is what to fix first.
By Jack Goldsmith, Founder & Performance Marketer, Social Surge · 8 September 2026
How do you optimise a Google Shopping product feed?
The highest-impact Google Shopping product feed optimisations are: front-loading search queries into product titles, achieving full GTIN coverage, completing all attributes Google marks as significant, and using custom labels to segment products by margin or performance tier for tighter bidding control. Feed quality is the single biggest lever available outside your bidding strategy, and in the accounts we manage, feed work regularly unlocks ROAS improvements before a single bid setting is touched.
Every advertiser running Google Shopping or Performance Max is competing in the same auctions, but not from the same starting position. Your product feed is the data Google uses to decide which searches trigger your listings, how prominently they appear, and at what cost. A weak feed puts a ceiling on what Smart Bidding can ever achieve. Google Shopping product feed optimisation is therefore not an optional enhancement; it is the foundation everything else sits on.
Unlike Search campaigns, where you write the ad copy, Shopping ads are generated entirely from your product data. Google reads your titles, descriptions, prices, images and attributes and uses them to match your products against user queries. When that data is thin, inaccurate or missing key attributes, Google's ability to match correctly is compromised. The result is typically lower impression share on high-intent queries, higher CPCs as Google compensates with broader targeting, and a Performance Max campaign that burns through budget on poor-fit traffic.
In the cycling accounts we manage, feed quality is the first thing we audit before any budget is touched. A bike shop with several hundred SKUs and weak product titles often has a significantly higher true ROAS ceiling than their current account suggests. The feed is simply not communicating the product correctly to Google's matching engine. Fixing it is the fastest route to better results, because it lifts the floor for every campaign running against those products.
Product titles have more influence on Shopping performance than any other feed attribute. They determine which queries trigger your listing and what a user sees before clicking. Google reads roughly the first 70 characters most prominently, so the structure of your titles matters as much as the words themselves.
The rule for most physical products is: Brand + Product Type + Key Specifications. A cycling example: "Shimano Deore XT M8100 12-Speed Rear Derailleur" outperforms "Bike Derailleur Shimano" in both impression quality and click-through rate. The first title matches specific buyer searches; the second matches broad queries where intent is weak and competition is high.
What to leave out: promotional language ("best", "great value", "sale now on"), internal stock codes, and anything that would not appear in a buyer's actual search query. Google's product title guidelines provide the full specification. The practical rule is to write for the searcher, not the warehouse management system.
GTINs (Global Trade Item Numbers, typically EAN or UPC codes) are optional in Merchant Center for most product types, but the performance impact of missing them is significant. Google uses GTINs to identify products in its own product catalogue and to place your listing alongside other sellers offering the same item. Without a GTIN, your products enter a weaker, less precise matching pool.
For branded products, GTIN coverage should be close to 100%. The barcode on the box is the GTIN; your supplier or the manufacturer can provide them if they are not already in your product data. For own-label or handmade items, Google allows the identifier_exists: false attribute, which removes the penalty for genuinely unique products. The full specification for product identifiers is in Google's product data specification.
Beyond GTINs, attribute completeness improves eligibility across campaign types. Every attribute Google marks as "highly recommended" has a measurable impact on reach. Common gaps we see on onboarding: product_highlight, size and size_type (especially for apparel and outdoor gear), material, age_group and gender. The Merchant Center diagnostics tab filters directly for these, showing you exactly which products are affected.
Custom labels are the mechanism that connects your feed data to campaign bidding strategy. You have five available (custom_label_0 through custom_label_4), each accepting a value you define. The most commercially useful approaches we use across our accounts:
Custom labels have no effect in isolation. They only do work when your campaign or Performance Max asset group structure is built to read them. If you are running a single PMax campaign across all products with no product groupings, the labels exist in your feed but nothing in the account is acting on them. See our guide on why Performance Max underperforms for the campaign structure context, and our bidding strategy guide for how target ROAS settings interact with product segmentation.
Shopping ad images cannot use overlaid text, watermarks or promotional graphics. Google enforces this and will disapprove listings that violate it. Beyond compliance, image quality directly affects click-through rate. A clean, white-background image of the product on its own typically outperforms lifestyle shots on Shopping (the opposite is often true on Meta). For outdoor and sporting goods in particular, multiple angles and size-reference images reduce return rates as well as improving pre-click conversion.
The minimum resolution is 100x100 pixels for most products, but anything below 800x800 will look poor in the Shopping carousel on desktop. Use the largest clean image your product photography allows, and ensure the image URL in your feed updates automatically when you change the product photo in your platform. A broken or cached image URL is one of the most common disapproval causes we see in new account audits.
A feed that was clean six months ago is not necessarily clean today. Prices change, products go out of stock, new variants are added with incomplete data. Google requires feeds to be refreshed at least every 30 days, but for e-commerce stores where pricing and stock fluctuate, a daily refresh is the practical minimum. Advertising an out-of-stock product or a price that differs from the landing page triggers disapprovals, and at scale, repeated violations can lead to account-level feed health warnings that restrict Shopping eligibility across the whole account.
The Merchant Center diagnostics tab surfaces every active issue, grouped by severity. The items most commonly missed: price mismatches (your feed price differs from the schema markup on the product page), image fetch errors (your CDN has blocked Google's crawler), and missing required attributes added in recent policy updates. Review diagnostics weekly. When we onboard a new account, the Merchant Center audit typically takes longer than the campaign audit, because the feed problems are usually the root cause of the campaign underperformance.
For a broader look at how feed issues connect to conversion tracking and Smart Bidding performance, see our guide on Google Ads conversion tracking for e-commerce. If you want a full account review that covers feed, campaigns and tracking together, our free PPC audit includes a Merchant Center diagnostic as standard.
Feed optimisation has diminishing returns. Stores with fewer than 50 SKUs should focus on titles, GTINs and images, and leave the custom label architecture until campaign volume justifies it. Stores with a single PMax campaign under 30 conversions per month will not see meaningful bidding improvements from label segmentation; Smart Bidding does not have enough signal to act on the additional structure. In that situation, the priority is building conversion volume first, and feed segmentation second. Our bidding strategy guide covers the conversion thresholds Smart Bidding needs to function correctly.
For cycling, fishing and outdoor accounts in particular, the feed is often where we spend the most time in the first 30 days, precisely because the category data (model numbers, compatibility specs, technical attributes) is rich and most stores are not exposing it in their titles. That gap between what a store knows about its products and what the feed communicates to Google is where significant ROAS headroom tends to live. If you want to know where yours is, the free audit will show you.
Product title optimisation delivers the highest return. Titles determine which search queries trigger your listings. Front-loading the most specific, buyer-intent keywords (brand, product type, key specs) into the first 70 characters improves match quality and click-through rate without any bid changes.
Yes. Google uses GTINs to match your products against its own product catalogue and to compare your listing against competitors selling the same item. Without a GTIN, your product enters a weaker matching pool, which typically means lower impression share and less competitive placement on Shopping and Performance Max.
Custom labels are five optional feed attributes (custom_label_0 to custom_label_4) you define yourself. Common uses include segmenting products by margin band, seasonality, stock status or performance tier. This lets you apply tighter ROAS targets to high-margin products and avoid over-spending on low-margin lines.
At minimum, daily. Google requires your feed to be updated at least every 30 days, but pricing and stock changes need to be reflected within hours, not days. Stale prices or advertising out-of-stock products triggers disapprovals and damages feed health scores. Most e-commerce platforms can schedule automatic feed refreshes via the Merchant Center Content API or a scheduled fetch.
Book a free PPC audit, full account review, wasted-spend analysis and a clear growth plan, delivered in plain English.
Book Your Free Audit