Advertising should be free of invalid activity – including unauthorized, misrepresented, and fake ad inventory – which diverts revenue from legitimate publishers and tricks marketers into wasting their money. Earlier this year we worked with the IAB Tech Lab to create the ads.txt standard, a simple solution to help stop bad actors from selling unauthorized inventory across the industry. Since then, we’ve shared our plans to integrate the standard into our advertiser and publisher advertising platforms.

As of November 8th, Google’s advertising platforms filter all unauthorized ad inventory identified by published ads.txt files:
  • Marketers and agencies using DoubleClick Bid Manager and AdWords will not buy unauthorized impressions as identified by publishers’ ads.txt files.
  • DoubleClick Ad Exchange and AdSense publishers that use ads.txt are protected against unauthorized inventory being sold in our auctions.

Preventing the sale of unauthorized inventory depends on having complete and accurate ads.txt information. So, to make sure our systems are filtering traffic as accurately as possible, we built an ads.txt crawler based on concepts used in our search index technology. It scans all active sites across our network daily, over 30m domains, for ads.txt files, to prevent unauthorized inventory from entering our systems.



The adoption of ads.txt has been growing quickly and the standard is reaching scale across publishers:
  • Over 100,000 ads.txt files have been published
  • 750 of the comScore 2,000 have ads.txt files
  • Over 50% of inventory seen by DBM comes from domains with ads.txt files

We believe ads.txt is a significant step in cleaning up bad inventory and it's great to have the broad support of our partners like L’Oreal, Omnicom Media Group, and the Financial Times.
“Consumers place enormous value on the ability to trust brands, which is why transparency in advertising is a top priority at L’Oreal. We look forward to collaborating with Google on this initiative as we continue to encourage the industry to follow suit.”
- Marie Gulin-Merle, CMO L’Oreal USA
"Removing counterfeit inventory from the ecosystem is critical to maintaining trust in digital. The simple act of publishing an ads.txt file helps provide the transparency we need to quickly reduce counterfeit inventory from harming our clients."
- Steve Katelman, EVP Global Strategic Partnerships, Omnicom Media Group
“It's great to see adoption of ads.txt across the industry and we're happy to see Google put their support behind this initiative. By eliminating counterfeit inventory from the ecosystem, marketers' budgets will work that much harder and revenue will reach real working media to fund the independent, high-quality journalism which society depends upon."
- Anthony Hitchings, Digital Advertising Operations Director, Financial Times

It’s amazing to see how fast the industry is adopting ads.txt, but there is still more to be done. Supporting industry initiatives like ads.txt is critical to maintaining the health of the digital advertising ecosystem. That’s why we’ll continue to invest and innovate to make the ecosystem more valuable, transparent, and trusted for everyone.

Posted by Per Bjorke
Product Manager, Google Ad Traffic Quality