Google Merchant Center.

Merchant Center holds a structured list of all the products a shop wants to show on Google: title, description, price, currency, availability, condition, image, brand, item number (GTIN) and shipping costs. This list is called the product feed. It can be synchronised automatically from the shop system, uploaded as a file or read in via structured data on the website. With Shopify, this is done through Google's official app.

With a well-maintained feed, products become visible in several places. Free of charge, they appear in the Shopping tab and in product sections of Google Search. As paid placements, they appear as Shopping ads that run through a linked Google Ads account, usually via Performance Max. For the retailer this means a single data source feeds organic and paid visibility at the same time.

Google checks the data strictly. Common reasons for rejected products are prices that do not match the price on the product page, missing shipping or returns information, images with promotional text or watermarks, and missing mandatory details such as a legal notice (Impressum) and contact options. The website itself is checked too: a shop without verifiable contact details can be suspended for misrepresentation.

The quality of the feed determines which search queries a product appears for, because Shopping ads have no keywords. Google matches the query to products via title, description and category. A title like 'Pan 28' therefore appears less often than 'Stainless steel frying pan 28 cm, induction-compatible'. Feed optimisation is thus a small SEO discipline of its own for product data. What the ads created from the feed look like is described under Google Shopping.