Two Shopping ads for the same product at the same price: one with stars, "free delivery in 24 h", "−15% with code" and "free returns"; the other, just an image and a price. The first one takes the click even if it bids less. This lesson is the shop window: the Merchant Center programmes and annotations that turn a flat ad into one that sells, plus the European piece that cuts your cost by 20%: CSS.
Promotions
Merchant Center → Marketing → Promotions. They show up as a "Special offer" on the ad, with the detail when you expand it. Types:
- Discount (percentage, amount, "2 for 1", on a minimum spend).
- Free or discounted delivery.
- Free gift with purchase.
- Coupon code (it must work at the checkout) or no code at all.
How to create them: one by one in Merchant Center, or through a
promotion feed (promotion_id, product_applicability
(all/specific), offer_type (with/without code), long_title, dates,
redemption_channel (online/in-store)). They get attached to products
by promotion_id in the product feed, or by filters (brand, category,
ID).
Approval requirements (manual review, up to 2-3 days): the promotion has to be verifiable on the website (landing page, a code that applies), with clear terms, no misleading "while stocks last", and it must meet the promotions policies. Rejected promotions can be edited and resubmitted.
The real effect: a CTR lift of several points on products compared by price; particularly powerful over Black Friday/sale periods with free delivery and exclusive coupons.
Reviews and ratings
Two different things:
- Product ratings (stars on the product): they need ≥50 reviews across the account in total and ≥3 per product before they show; sources: your own product review feed (XML in Google's schema), approved aggregators (Trustpilot, Yotpo, Judge.me, eKomi, Verified Reviews…), or Google Customer Reviews (with the product survey). With a GTIN, Google aggregates reviews from other sellers of the same product.
- Seller ratings (the shop's stars, on Search and Shopping): they need ≥100 reviews over 12 months and a score of ≥3.5; sources: Google Customer Reviews (free: a pop-up after purchase + an email survey), aggregators, Business Profile reviews and Google users.
Google Customer Reviews: an integration with a script on the confirmation page (order, email, estimated delivery date, products with a GTIN to rate); an optional badge on the website. It is the quickest free route to seller stars.
Automatic badges and annotations
Google adds these when the conditions are met; all you do is feed it the data:
| Badge / annotation | Condition |
|---|---|
| Price drop | sale_price below the usual price over the last 30 days |
| Fast / free delivery | Shipping services configured with delivery times and zero cost (or shipping in the feed) |
| Free returns / returns window | A returns policy declared in Merchant Center with zero cost and a window |
| Available nearby / in store | Local inventory |
| Best seller / popular / trending | Google's market data |
| Stars | Reviews (above) |
| Unit price | unit_pricing_measure |
| Instalments / payment plan | installment in the feed (where it applies) |
Every badge is free CTR. The list of "what I am missing" lives in Merchant Center → Growth/Opportunities.
Free listings
With the account and the feed approved, Google shows your products at no cost on the Shopping tab, on Search (product listings), Images, Maps and Lens. You switch it on under Programmes → Free listings. Same requirements as the ads (policies, data). Performance appears in the report by destination (lesson 5). This is the reason to keep the catalogue immaculate even when the spend is paused.
CSS in Europe: the 20% almost nobody claims
Following the European Commission's decision (2017), in the EEA, Switzerland and the UK, Shopping ads can be served through a Comparison Shopping Service other than Google Shopping. The mechanism: Google Shopping (acting as a CSS) keeps a margin; third-party CSSs take part in the auction without that margin, so the same budget buys about 20% more (Google documents it as bids placed through third-party CSSs not including Google Shopping's margin).
How it works in practice:
- Choose a CSS partner (there are dozens: Producthero, Redbrain, Shoptimize, Kelkoo, idealo, Shopping Ads CSS…; either a flat monthly fee or a percentage model).
- The CSS associates your Merchant Center account with its CSS account (Merchant Center → Programmes → CSS). The Google Ads account and the campaigns remain yours.
- The ad shows "By [CSS name]" instead of "By Google".
- The result: lower effective CPCs at the same position (the saving observed in real accounts is usually between 10 and 20%).
It is worth it for any shop with meaningful Shopping spend (the CSS fee is smaller than the saving from a few hundred euros of monthly spend upwards). Some CSSs also offer feed tools, which ties in with lesson 6.
Other programmes
- Buy on Google / checkout (where it exists): the purchase happens inside Google; demanding logistics requirements.
- Local inventory ads and the local storefront (lessons 13.5 and 14.8).
- Brand programme / Manufacturer Center: if you are the manufacturer, enriched data about your products for every seller.
- Dynamic remarketing: the Merchant Center feed powers dynamic Display/Demand Gen/PMax ads (Intermediate Display, Advanced M12).
- YouTube Shopping: products in videos and on the channel.
Which programme by type of shop
| Shop | Priority |
|---|---|
| Small (< €1,000/month) | Free listings, Customer Reviews, delivery/returns badges, 1-2 promotions |
| Medium | + CSS, promotion feed, product ratings |
| Large / multi-brand | + Merchant API, Manufacturer Center, local inventory, multi-client |
💡 Ninja trick: the order in which CTR improves in Shopping, from most to least impact and from least to most effort: a competitive price → delivery/returns annotated → seller stars (Customer Reviews, free) → a seasonal promotion → product ratings. And in Europe, CSS does not improve CTR but it lowers the cost of every click: it is the best effort-to-return decision in Shopping, and the most ignored.
What to remember
- Promotions (feed or manual, verifiable) = "Special offer" and CTR.
- Reviews: product ratings (≥50/≥3) and seller ratings (≥100 over 12 months, ≥3.5); Google Customer Reviews is the free route.
- Automatic badges (price drop, delivery, returns, popular) are earned with correct data.
- Free listings: visibility at no cost from the same catalogue.
- CSS in Europe: around 20% more bidding power on the same budget; it is nearly always worth it.