Anonymised URLs are being deprecated for the Google Display Network, in order to be compliant with Ads.txt requirements.
Question 1: Why do I see URLs other than 'xyz.anonymous.google.com' in my reporting even though I had specifically targeted anonymised inventory?
In the past, we’ve allowed publishers to choose to offer placements anonymously and didn't disclose their site names to advertisers. However, to comply with Ads.txt requirements, we're no longer allowing publishers to choose to remain anonymous. This means that we're now showing the exact URL where your ad was served. If you had previously targeted a pseudonymous placement (e.g. 'xyz.anonymous.google.com'), we've replaced that with the de-anonymised placement of the publisher that you've been targeting.
This change only impacts reporting. We're still adhering to all of the configurations (such as bidding, targeting, conversions, etc.) specified in your campaign settings.
Question 2: What is Ads.txt?
Ads.txt is a tool introduced by the Interactive Advertising Bureau Tech Lab to create transparency for advertisers, publishers and other stakeholders in the online advertising industry. Publishers host a publicly available .txt file that lists all sellers authorised to sell their inventory that exchanges (and anyone else interested) can reference to prevent inventory fraud.
For example, once an ad buyer knows the placement that their ad served on, they can then check the publisher's ads.txt file to verify that they purchased their inventory through an authorised seller. This page on the IAB’s website explains in more detail how these .txt files are used.