MediaRadar Blog

checkmark laptop

Ads.txt Explained: Who’s Buying In?

In 2017, the conversation surrounding transparency in advertising gained quite a bit of traction, as many brands expressed their distrust in the high levels of fraud surrounding them.

Within that conversation, emerged a new tool, known as Ads.txt.

The idea for something like this had been lingering in the back of the industry’s mind, but never received the proper support to become a reality. This year’s intensified conversation surrounding brand safety made it possible, however.

MediaRadar CEO, Todd Krizelman, stated, “The idea for this (ads.txt) has been around for years, but the raft of fraud this year really motivated the industry to get on board – especially for brand-name publishers.”

By backing the use of ads.txt, brand-name publishers are doing their due diligence in keeping the matter top-of-mind.

And while we fully expect the focus on brand safety to intensify, now seems to be the perfect time for publishers to capitalize on these lingering concerns and adopt ads.txt.

Strangely enough, however, it seems to be taking a bit longer than we would’ve thought.

How does ads.txt work?

Ads.txt is a tool that helps maximize transparency between publishers and the advertisers they sell to. It was introduced in mid-2017 by the Interactive Advertising Bureau (IAB).

The tool lets ad buyers know, without question, whether or not the ad space they’re purchasing is legitimate. It is a way to minimize ad fraud.

According to Todd Krizelman, ads.txt is “a straightforward way to stop advertisers from buying counterfeit ad inventory.”

But how exactly does it work?


For publishers, ads.txt is simply a text file. They take that text file, and drop it into their web server. Once the text file is placed, the tool qualifies two things for publishers:

First, it maintains a list of authorized platforms – only these platforms can sell their inventory.

Secondly, ads.txt can also identify the platforms that are not permitted to sell a publisher’s ad space.

Fittingly, the “a-d-s” in the name “ads.txt” is actually an acronym. It doesn’t simply stand for “ads,” but instead stands for “Authorized Digital Sellers.


Selling platforms and advertisers can also use ads.txt to their advantage.

Programmatic platforms can integrate ads.txt files to confirm, on their end, which publisher’s inventory they are authorized to sell – to again eliminate faulty inventory sales.

Because of this, advertisers can check the legitimacy of the inventory they are looking to purchase.


Working through the “kinks.”

That being said, ads.txt, of course, is not perfect. Things of this nature take time to build and master.

In implementing text files, there can be minor formatting issues and publisher typos that prevent the tool from running as expected.

But, while ads.txt is not yet immune to typos, it is moving the industry in a much needed direction. This is why companies are, albeit a bit slowly, buying in to the tool, and into the idea of transparency.

Who’s buying in?

MediaRadar recently observed 3,000 publisher sites to gain a bit of insight into who is adopting ads.txt.

Out of those 3,000 publisher sites, MediaRadar found that only 20% were currently implementing ads.txt.

After seeing it’s moderate adoption, Todd Krizelman added, “After six months, the largest sites are moving quickly, but only 20% of all publisher sites we track today have taken advantage of ads.text. It’s a reminder of the power of inertia, and the importance to really evangelize the benefits of this new way to stop spend on unauthorized counterfeit ad inventory.”

The overall message here, is that publishers of all sizes should be discussing the benefits available in implementing ads.txt. For more on implementing ads.txt, check this blog out by MonetizeMore.

Much like the brand safety conversation suddenly gained large amounts of traction, advertisers can only hope the same happens with this new tool.

And while adoption of the tool itself is very important for publishers, the main importance in doing so lies in showing that they buy into the ideas of brand safety and transparency.