What is the purpose of utilizing supplemental feeds alongside the primary product feed in Google Merchant Center?

The purpose of utilizing supplemental feeds alongside the primary product feed in Google Merchant Center is to update or enrich existing product data without modifying the main feed. The primary feed contains the core product information required by Google, such as ID, title, description, price, and availability. Supplemental feeds allow you to provide additional data or override existing data in the primary feed for specific attributes. For example, you can use a supplemental feed to update prices frequently based on real-time market conditions, add promotional labels for specific products during a sale, update inventory levels to reflect current stock, add missing GTINs (Global Trade Item Numbers) if they were initially omitted from the primary feed, or provide custom labels for advanced campaign management. Supplemental feeds are linked to the primary feed using a unique identifier, such as the product ID. This allows Google to match the data in the supplemental feed to the corresponding products in the primary feed. Using supplemental feeds simplifies product data management, especially when dealing with large product catalogs or frequently changing information. It also helps prevent errors by isolating updates to specific attributes rather than requiring a complete re-upload of the primary feed.