Google announced the introduction of inventory controls in its Google Marketing Platform, specifically within Display and Video 360 (formerly DoubleClick Bid Manager) allowing advertisers to selectively choose to buy from websites which exclusively support ads.txt authorized inventory and exclude themselves from buying inventory from sites not using the ads.txt file.
The recently released Display and Video 360 (formerly called DoubleClick Bid Manager), a part of the Google Marketing Platform, allows advertisers to execute ad campaigns end-to-end in one place, creating efficiency in how teams work and helping teams do more together. For more on Display & Video 360.
Ads.txt allows publishers to place on their website server a .txt file which explicitly lists which companies they sell their inventory through. The file lists partners by name, but also includes the publisher’s account ID.
This is the same ID buyers see in a bid request, which they can use as a key for campaign targeting. Buyers use a web crawler to download all the ads.txt files and the information contained within on a regular basis and use it to target their campaigns. This means buyers know that if they bid on request that comes from an authorized ID, it’s coming from a source the publisher trusts or has control over.

Originally launched in Q4 2017, Ads.txt has proved to be highly adopted and successful.
According to a blog post written by Tobias Maurer, Google senior product manager, ads.txt is making a big impact on the industry.
Nearly 600,000 publishers have adopted ads.txt since October 2017, specifically, 430,000 domains have added ads.txt files to their website since February 2018.
“We’re proud to say that nearly 90 percent of our publisher partners have adopted ads.txt.
What’s more, over 80 percent of the available inventory across exchanges accessed by Display & Video 360 is now authorized.
Finally, as more websites continue to adopt the standard, we plan to make the ads.txt-only inventory control the default setting for Display & Video 360 by the end of 2018. said Maurer.”
For more information about Ads.txt: