Shopping in depth V: the Merchant Center reports nobody looks at — price competitiveness, best sellers, margin and listing performance

In short: Merchant Center has data Google Ads doesn't: market prices, the best sellers in your category even if you don't sell them and your real margin if you give it the cost of goods. Price competitiveness explains why a product doesn't sell even though you bid: price decides before the bid does. With margin, ROAS becomes POAS.

Google sees every shop and every price. Part of that view comes back to you in Merchant Center, in reports almost nobody opens because "the data is in Google Ads". It is not: Google Ads holds your clicks; Merchant Center holds the market's prices, what sells in your category even when you do not stock it, and your real margin. This lesson walks through them and turns them into decisions.

1 · What is the price competitiveness report?

Merchant Center → Performance/Analytics → Price competitiveness. It needs a GTIN (to match against the catalogue) and other shops selling the same products.

What it shows by product, brand and category:

• Your price vs the benchmark price (a click-weighted average across the advertisers selling the same product).
• The difference (%): above, level, below.
• How it has moved over time.

How to read it:

Price is the first driver of CTR and conversion in Shopping: a product 15% dearer than the benchmark needs an impossible tROAS. This report tells you which products bidding cannot fix.

2 · What are Google's suggested prices?

Google simulates what would happen at another price: for each product, a suggested price, the projected clicks and revenue, and the effect on margin if you supply cost_of_goods_sold. It is a model (take it as a hypothesis), but useful for spotting products where a small cut sets off clicks and conversions (high elasticity) and products where a rise costs you no sales.

3 · How do you find out what sells in your category?

Best sellers: the best-selling products and brands on Shopping by country and category, with their rank, relative demand and — most valuable of all — whether you stock them or not, and the average price they sell at.

Uses:

• Assortment: what sells in your category and you do not sell = candidates to bring in (or to stop chasing, if the market price sits below your cost).
• Prioritising the catalogue: your products that are market best sellers → a custom_label "bestseller" → a protected campaign.
• Trends (the "fastest-growing" view): seasonality and new arrivals before your own account history shows them.

4 · How do you see real margin in Merchant Center?

If the feed carries the cost of each product, Merchant Center (and Google Ads in its conversion reports) works out the gross profit per product: revenue − cost of goods sold. That is what enables the jump from ROAS to POAS (profit on ad spend): two products on a ROAS of 4 can have opposite profits. With the margin per product visible:

• tROAS per campaign by margin (lesson 4) stops being an estimate.
• You spot products that "convert" and lose money.
• You can bid to conversion value = margin (sending the margin as the value instead of revenue; a measurement decision).

5 · How do you see performance by product and destination?

Merchant Center → Performance: clicks, impressions, conversions (if you have the tag) by product, brand, category and destination:

• Shopping ads (what you pay for).
• Free listings (the Shopping tab and other surfaces at no cost — with the account and the feed approved, they appear on their own).
• Local inventory, Buy on Google, and so on where they exist.

How to read it: products with many free impressions and few paid ones (or the other way round); products with clicks and zero conversions (price, product page, stock); categories with growing free impressions → a demand signal. Free listings are also the argument for keeping the catalogue perfect even when you are not paying: visibility at no cost.

How do you cross Merchant reports with Google Ads?

The decision comes out of the cross-reference: price (Merchant Center) + advertising performance (Google Ads) + margin (the feed). A table per product with those three columns is the control panel of any ecommerce business.

🔧 The Shopping Ninja script solves this: it builds exactly that per-product table — Google Ads performance cross-referenced with the real sales and margin the client fills in on the spreadsheet (POAS), with a traffic light and checkbox actions (exclude a product, negativise a term, propose a title). The Merchant Center reports (competitiveness, best sellers) are consulted in Merchant Center and poured into the spreadsheet as manual columns, which the script preserves on every run.

What to remember

• Merchant Center holds data Google Ads does not: market prices, the best sellers in your category, margin with cost_of_goods_sold and performance by destination (free listings included).
• Price competitiveness explains why a product does not sell however hard you bid: price decides before the bid does.
• Best sellers = assortment and prioritisation; margin = from ROAS to POAS.
• The per-product decision comes from the cross-reference of price + performance + margin — in a table, ideally an automated one.