The first useful screen in a Shopping review is usually Merchant Center diagnostics, not the bidding tab. Start there. Bids feel like the active part of the account, so they attract attention. The feed decides whether a product is eligible and what Google can understand about it before an auction starts.
Take a catalogue with 14,000 SKUs. If diagnostics shows 2,100 products disapproved or limited, 15% of the range is constrained before a bid is placed. That is the first number to investigate. The remedy may be an identifier, availability mismatch, policy issue or landing-page problem, so diagnose the reason before touching campaign targets.
Titles do the heavy lifting
Google matches search queries against your product titles. A title like “Aria” tells the algorithm nothing. “Aria linen midi dress, navy, sizes 36 to 46” enters the auction for “navy linen midi dress” and half a dozen related queries.
Start with the real product name, then add the attributes shoppers use to distinguish it, such as product type, material, colour, size or model. Put the most informative terms early and keep promotional language out. Google’s product data specification is the source of truth for required fields. Test title changes on a defined product group and compare impressions, click-through rate and conversion value at stable bids.
GTINs are not optional paperwork
When a manufacturer has assigned a GTIN, submit it accurately. Google uses product identifiers to understand the item and match it to catalogue data. Missing or incorrect identifiers can limit performance or trigger item issues. Never invent a GTIN for a product that does not have one.
Run the check by category: what share of products that should have a GTIN carries a valid one? Trace the gap back to supplier data, the ERP or the feed mapping. There isn’t a universal pass mark. The reason each identifier is missing matters.
Stale availability is the quiet budget leak
If your feed syncs once a day and your best sellers move fast, you’re paying for clicks to out-of-stock pages every afternoon. Worse, price and availability mismatches between the feed and the landing page are a classic disapproval trigger.
Set the sync frequency from stock velocity. For a fast seller, calculate the exposure directly: out-of-stock ad clicks multiplied by average CPC, plus the conversion value lost when a shopper lands on an unavailable product. If that number rises on weekends, a nightly sync is too slow.
Categories decide which race you’re running
The google_product_category attribute gives Google another signal about what the item is. Use the most specific valid category that fits the product, rather than forcing a broad parent category across the catalogue. For example, a blender belongs under the blender leaf instead of the broader Home & Garden parent.
Where to start on Monday
- Open Merchant Center diagnostics and clear the disapprovals. This is the closest thing to free money in paid media.
- Read the titles on your 100 best sellers as if you were the shopper. Would the query match?
- Check GTIN coverage per category.
- Compare your sync frequency to how fast your top SKUs actually sell.
- Check category mapping depth. Leaf categories, not top level.
Feed work is unglamorous, which is exactly why it’s still an edge. Most of your competitors will keep fiddling with bid adjustments on top of a broken catalogue. Do the feed first. Every improvement you make there multiplies the return on everything downstream.