If you run Google Shopping or Performance Max, there's a reasonable chance the biggest performance lever in your account isn't in Google Ads at all. It's sitting in Merchant Center, in a spreadsheet or a feed app, and it hasn't been looked at properly since the account was set up.

Shopping ads don't have keywords. Google decides when to show your products by matching the search query against the data in your product feed. That means the feed is your targeting, your ad copy and a good chunk of your bidding signal, all rolled into one. Optimising campaigns while ignoring the feed is like tuning a car with the handbrake on.

Here's what actually matters in a product feed, roughly in order of impact, and how to approach it without turning it into a never-ending project.

Why the feed matters more than most brands realise

Three things in Google's system depend heavily on feed quality:

  • Eligibility - products with missing or disapproved attributes don't show at all, and you often don't notice because nothing looks "broken" in the campaign
  • Relevance - the title and description determine which searches your product is matched to. Poor titles mean either no impressions or the wrong ones
  • Click-through rate - the title, image and price are the ad. If they're weak, you pay more for every click that does happen

Performance Max leans on the feed even harder than standard Shopping did, because the system is doing more of the matching on your behalf. A clean, descriptive feed gives it better raw material. A lazy one gives it guesswork.

Titles: the single highest-impact change

Product titles are where most of the value lives, and most brands are feeding Google whatever their website's product name happens to be. "Classic Tee - Navy" is a fine product name on a website. As a Shopping title it tells Google almost nothing about what someone would search for.

A strong title front-loads the information people actually type: brand, product type, key attribute, then the distinguishing details. Something like "Brand Name Men's Organic Cotton T-Shirt - Navy - Slim Fit" gives the matching system far more to work with, and tells the shopper what they're clicking on before they click.

A few practical rules:

  • Put the most important words in the first 70 characters - that's roughly what shows in most placements
  • Include the attribute that drives the search in your category: size for furniture, material for clothing, compatibility for parts and accessories, colour for homewares
  • Don't stuff keywords or add promotional language - "SALE!!" in a title gets flagged and looks cheap
  • Use your search terms report to find the phrasing customers actually use, then mirror it

You don't have to rewrite your website to do this. Title rules in Merchant Center, a feed management tool, or a supplemental feed let you build Shopping-specific titles from existing attributes without touching the site.

Product type and Google product category

Google product category is the standardised taxonomy Google uses to understand what you sell. Product type is your own free-text categorisation. Both matter, for different reasons.

Google product category should be as specific as possible - "Apparel & Accessories > Clothing > Shirts & Tops" rather than just "Apparel & Accessories". It feeds relevance and, for some categories, determines which attributes are required.

Product type is arguably more useful to you, because it's how you'll segment campaigns, build asset groups and read reports. A consistent, hierarchical product type - "Men > Tops > T-Shirts > Organic" - lets you split spend by margin, season or range later without rebuilding anything. Most feeds I audit either have it blank or have forty inconsistent variations of the same thing.

Images, price and availability

Shoppers see the image before they read a word. A clean product shot on a white or very plain background, filling the frame, consistently outperforms lifestyle imagery in standard Shopping placements. Keep lifestyle images for the additional image slots and for Performance Max assets, where they do earn their place.

Price and availability need to be accurate to the minute, not the day. Mismatches between the feed and the landing page trigger disapprovals, and intermittent "price mismatch" errors are a reliable sign the feed isn't refreshing often enough. If you run promotions, use the sale price attributes properly so the strikethrough shows in the ad - it meaningfully improves click-through rate when the discount is real.

Identifiers: GTIN, brand and MPN

Unique product identifiers let Google match your product to its catalogue of everything else being sold, which unlocks richer results and better matching. Missing GTINs where they exist is one of the most common reasons products under-deliver quietly. If you sell your own branded products without barcodes, set the identifier-exists attribute correctly rather than leaving it blank or making numbers up - the latter gets caught.

Custom labels: the attribute everyone ignores

Custom labels do nothing for Google's matching. They exist purely so you can segment your own products for bidding and reporting - and that makes them one of the most commercially useful fields in the whole feed.

Sensible things to label:

  • Margin band - high, medium, low - so you can set different ROAS targets by profitability rather than treating all revenue as equal
  • Price tier - so you can see whether your £15 products and your £150 products need different treatment
  • Seasonality - so winter stock can be pushed in October and pulled back in February
  • Bestseller or new-in status - so new products get a chance to gather data and bestsellers get protected
  • Stock level - so you stop pouring budget into products with three units left

With labels in place you can split campaigns or asset groups by what actually matters to the business, instead of by whatever the website's category structure happens to be.

Diagnostics you should check monthly

Merchant Center's diagnostics tab is where feed problems announce themselves, and it's remarkable how rarely anyone opens it. Once a month, at minimum:

  • Review disapproved and limited items - and fix the underlying cause, not just the individual product
  • Check the share of products that are actually active versus submitted. If 20% of your catalogue isn't eligible, that's 20% of your potential revenue not being shown
  • Look at the item-level report for products with high impressions and very low clicks - that's usually a title, image or price problem
  • Look for products with lots of clicks and no sales - sometimes a feed issue sending people to the wrong variant, sometimes a landing page problem

Where to start if the whole thing feels overwhelming

Don't try to perfect the entire catalogue. Pull a report of your top 20% of products by revenue and fix those first: titles, product type, images, identifiers. That's typically where 70-80% of the Shopping revenue comes from, and the improvements compound quickly. Then set up custom labels so the account can be structured properly. Then work through the rest in batches.

Feed work isn't exciting. Nobody puts "rewrote 400 product titles" on a slide. But when a Shopping account that's been flat for a year starts growing again, the feed is very often the reason. If you'd like an honest view of where yours stands, it's one of the first things I look at in any eCommerce paid media review.

Related Reading