Google Merchant Center
Also known as: Merchant Center, GMC
In short
Google’s service for providing and managing business and product information used in shopping experiences, including free listings and product advertising.
Manage the product information behind listings
Merchant Center holds business and product information that Google uses across shopping experiences. Merchants provide information about what they sell, where they sell it and the terms of their offers.
It serves a different purpose from Google Ads. Merchant Center manages the product information; Google Ads manages advertising campaigns, budgets and bidding. Linking the accounts enables advertising campaigns to use the relevant product data.
Product information can come through supported connections and data sources. Processing that information is separate from approving a product or actually showing it to a shopper.
Illustrative example
Imagine a shop uploading its lighting assortment. Merchant Center processes item identifiers, prices, images and availability. A product with an issue requires investigation even if the upload itself completed.
The advertising team then uses eligible products in a linked Shopping campaign. Changing the campaign budget happens in Google Ads; correcting an incorrect product price belongs in the source data workflow.
Check the offer after processing
Do not treat an account connection as proof that every item is ready to appear. Review product issues and verify that landing pages and checkout agree with submitted details. Keep business information accurate as well. A clean file cannot compensate for an offer that customers cannot purchase as described.