Google Merchant Center is telling me that I will have a limited performance due to missing value [GTIN]
GTIN (Global
Trade Item Number)
values are a unique identifying label that is assigned by the product manufacturer / supplier. They are unique for each product and every retailer that sells the same product will have the same GTIN value for each product. As they are assigned by the product manufacturer they cannot be self-created (unlike SKU codes).
Google informs us that the performance of your ads will be improved if you enter the GTIN value for each of your products. This is because it is another piece of data that Google's machine learning can use to increase the performance of your ads. It can reference what has worked to sell the products with the same GTIN values through the Google Ad platform before and replicate what has worked for your campaign.
The GTIN value for each product can also be called the product barcode or UPC and in fact to assign your GTIN values to your products, you will enter your GTIN values into the barcode field for your product in Shopify.
If you are missing GTIN values for your products, your suppliers should be able to provide the GTIN codes for each of their products if you just ask them to send them across.
Once you have entered your GTIN values into the barcode field for your product in shopify, they will then be pulled through onto your Merchant Center account by the Simprosys Shopping Feed App. After 24 hours, the notification of limited performance should no longer be there if you have entered your GTIN values correctly.
If your suppliers cannot provide GTIN values for each of their products, this will not prevent you from being able to run ads. However, Google will inform you that your performance will be limited.