Google Merchant Center may have recently added to the product feed report the number of products found by Google, not by way of a feed you provided or manually submitted but automatically found through crawling or other means.
As a reminder, Google Merchant Center Next is now available to all and everyone will switch to it. Part of this is Google automatically crawling your site to add products automatically, like it does with promotions.
Casey Gill spotted this new field in the Google Merchant Center product feed that says "more found by Google." She posted about it on LinkedIn and here is a screenshot:
Casey wrote, "And if you didn't already appreciate the connection between SEO and PPC, now you will." "Merchant Center Next is finding products by crawling sites. This can add more products automatically, even if they aren't submitted in your feed. In order for website crawls to work, you need structured data markup on all product landing pages. The idea is this will soon make the cumbersome management of data feeds a thing of the past," she added.
Forum discussion at LinkedIn.