What is the CID parameter in Google shopping URL?

Question

I noticed the existance of "cid" parameter in every product page I examined in Google Shopping website? Can we depend on this parameter to uniquely identify each product? Is it possible that Google will use the same parameter value for another product in the future?

Answer 1

Yes, cid is used to uniquely identify a product.

Answer 2

The CID stands for the Customer ID, this is an ID unique to the visitor and should not be used for the product. The CID is a universally unique identifier (UUID) and is a 128-bit number used to identify information in computer systems. This value is stored in the _utma Google Analytic Cookie to track the device it is assigned to. Additional reference: https://developers.google.com/analytics/devguides/collection/protocol/v1/parameters#cid