Multiple vendors have conducted their own research around ads.txt, so there are various adoption rates floating around the industry. For instance, MediaRadar found that only 20% of the 3,000 sites in its panel had adopted ads.txt. OpenX found that 54% of the largest 1,000 publishers in terms of comScore Inc. traffic had adopted ads.txt.
There are discrepancies across these vendors because they each measured a different sample. When Pixalate analyzed the top 5,000 websites regardless of whether they sold programmatic ads or not, 22.4% of the sites had adopted ads.txt, which is in line with MediaRadar’s findings.
The push for ads.txt has advocates across the entire supply chain. Some ad buyers have demanded that publishers adopt ads.txt if they want to be included on campaigns. Several programmatic platforms including Google and The Trade Desk have built filters in their dashboards that allow advertisers to filter inventory by whether or not it is ads.txt verified. Industry groups like Trustworthy Accountability Group (TAG) have also made ads.txt a part of their accreditation process.
While ads.txt can help ad buyers avoid unscrupulous sites that pretend to be something they’re not, it isn’t a foolproof way to avoid domain spoofing because publishers misspell and mislabel vendors in their ads.txt files. If ads.txt is to become more effective and easier to navigate, publishers will have to clean up their act since 16% of publishers’ ads.txt files have errors, according to FirstImpression.io.