Due to the new Google rules, now the publishers must declare who is authorized to sell advertisements on their site, through an initiative that was developed by the OpenTab group of IAB TechLab, with full support from Google.
For more information you can access the following links:
In order to make this verification possible, the publisher simply needs to add the ads.txt file to the site files, which must contain the necessary information, detailed below. It must be entered in the main directory of the website, in the root domain. For example: https://grumft.com/ads.txt.
In a simple way, the file contains 4 informations:
The use of the file aims to make "publishers vs. resellers" relationship more transparent and secure, so as to be easier to verify whether the reseller is authorized to use the website space for uses of programmatic advertising.
In this way, it inhibits an unauthorized user to sell space, damaging a profitability of the site.
The Grumft has prepared for our publishers a file with that information, which can be downloaded in this e-mail or in our platform: gpub.grumft.com.
If the page already has the file, relevant to another reseller's account or a direct sales account, the specifications of our file should be included in the existing file. The domain must have only one ads.txt file.