What is ads.txt:
Ads.txt is an initiative from The IAB Tech Lab. The main goal to increase transparency in the programmatic advertising ecosystem. It is a simple method for publishers to declare who is authorized to sell their digital inventory.
The publisher puts a text file on his web server on the root level of the domain, it must be called ads.txt, and it must have its Read permissions set to “World”. The file must follow the IAB format (see below).
The file should list all of the companies that are authorized to sell the publishers’ inventory. This page will be crawled by DSPs and the information will later be checked against incoming bid requests to validate that the advertising system the ad request is coming from is authorized to sell the publisher's inventory.
Why it matters:
If you are a Publisher, ads.txt will help you retain control over who sells your inventory - It will help you improve the quality of the ads shown, block unauthorized arbitrage and improve the overall user experience of your website. Furthermore, complying with this initiative will show advertisers that your website is trustworthy and brand safe for their ads.
60% of the comScore 1000 publishers have already implemented ads.txt on their sites and this percentage will only increase
Publishers who are ads.txt compliant will be able to sell their inventory in curated markets - today major DSPs are already giving the option to advertisers to filter-out inventory that is not ads.txt certified
Learn how to implement ads.txt here.