The product feed is the foundation; on top of it, Merchant Center supports other feeds and programmes that enrich the listing: an offer annotation, review stars, availability in a physical shop. Each one lifts CTR measurably; each one has its own requirements. This lesson introduces them and puts them in order.
Promotions
A promotions feed (or manual creation in Merchant) defines offers:
discount code, percentage, free shipping, gift, with dates and the
products they apply to (all of them, or via promotion_id in the
product feed). Once the promotion is approved, the listing shows a
special offer annotation with the detail on click. Effects: it lifts
CTR noticeably and competes better in carousels. Requirements: the
promotion must be real and verifiable on the website (Google reviews
it), time-limited, and compliant with policy (no "permanent offer").
Typical use: seasonal sales, first-purchase codes, free shipping above a
given amount. With sale_price already visible, the promotion adds the
second layer (the code or the shipping).
Product ratings
Stars under the listing (average rating and number of reviews for the product, aggregated across shops when there is a GTIN). Routes:
- Your own product review feed (if you collect reviews on your site, in a format Merchant accepts) — requires a minimum number of reviews.
- Review aggregators integrated with Google.
- Reviews Google already has for the product (via GTIN) even if they are not yours.
The correct GTIN (module 6 of Intermediate) is what connects your listing to the reviews in the global catalogue.
Seller ratings
The shop's rating (stars next to the seller name) comes from customer opinions collected by Google (the Google Customer Reviews survey after purchase) and from recognised review platforms. It requires a minimum number of reviews over 12 months and a minimum score. Switch on Google Customer Reviews (a snippet on the order confirmation page): it is free and it feeds the seller stars in Shopping and in text ads.
Local inventory and physical shops
For businesses with shops: the local inventory feed (products, shops and stock per shop) and the local products feed enable local inventory ads: the listing shows "in stock at your shop X km away" and leads to a local storefront or to your site. Requirements: a verified Business Profile per shop, inventory feeds kept up to date (daily or more often), and inventory verification by Google. It is the bridge between Shopping and the physical shop, with store visit measurement if the account has it enabled.
Other verticals
Specific feeds with their own specifications: vehicles (vehicle inventory ads for dealerships), hotels (hotel campaigns with price feeds), flights, travel, education, jobs, real estate (business feeds for dynamic remarketing). Each has its own module in Merchant or in Google Ads; the logic is always the same: a structured feed + a campaign that reads it + annotations on the ad.
Prioritising
| Business | Switch on first |
|---|---|
| General ecommerce | Seller ratings (free, lifts CTR everywhere) → promotions in season → product ratings if you collect reviews |
| Own brand with few external GTINs | Your own product reviews (they will be the only ones there are) |
| Physical shops + online | Local inventory (the differentiator against pure online sellers) |
| Dealership, hotel, estate agency | Their vertical's feed |
| Everyone | Real promotions with dates; never permanent ones |
Typical mistakes
- "Permanent" or unverifiable promotions: disapproval and loss of trust in the shop.
- Reviews bought or imported from unsupported sources.
- Out-of-date local inventory: "in stock in shop" and it is not.
- Forgetting that every extra feed is another diagnostic to review.
💡 Ninja trick: offer annotations and stars are listing CTR (module 5 of Intermediate), and listing CTR is what decides which product wins the slot. Shopping Ninja flags products with good CTR but poor conversion (a promise the landing page does not keep) and those with low CTR but good conversion (a poor listing: no reviews, no offer, a weak image) — the latter are the natural candidates for a promotion or a better listing.
What you should remember
- Promotions that are real and dated → offer annotation; product ratings (via GTIN and feeds) and seller ratings (Google Customer Reviews, free) → stars.
- Local inventory for physical shops: the differentiator.
- Verticals with their own feeds (vehicles, hotels, real estate…).
- Prioritise: seller ratings → seasonal promotions → product ratings → local if you have shops.