This article helps to double-check the setup for the product reviews feed in Google Shopping.
Please keep in mind that you need a minimum of 50 reviews across all of your products so that Google will consider your product reviews. https://support.google.com/merchants/answer/6059553 (see headline 'Eligibility').
Check which value has been entered in the product admin SKU field. You should find this value in your product feed and in your product reviews feed. Adding a GTIN in the barcode field is recommended.
Check that the app you use to create your product feed is actually using the field
SKU to create the product ID in the products feed. The screenshot shows an example for Google Shopping Feed app.
Investigate your product feed app and verify that SKU will be used for the id field.
Go to the Google Merchant Center and check your product feed (you can usually go directly to the Merchant Center from your product feed app).
Check if you can find all relevant information (SKU, optionally GTIN and MPN) in the XML feed.
You can optionally include the MPN field in the product reviews XML feed. This will add one further row (MPN) that will have the same value as
Open the product reviews XML feed and check if the feed has been properly created. You should easily find (Mac:
Command ⌘ + F, Windows:
CTRL + F) your SKU in the feed.
Problem: The following error message is shown
Pre-processing report not created A pre-processing report has not been created for this upload due to product data being sourced from both primary and supplemental feeds. Review and take action on the results of your processed data in the diagnostics section.
for your product reviews feed (supplemental feed)
Solution: Please fix issues in the diagnostics section. Your supplemental feed might not be matching your main feed.