Skip to main content


During the summer of 2017, many publishers either questioned or quickly adopted an initiative from the IAB Technology Laboratory called ads.txt. This technology contains a text file that companies can host on their web servers which list other companies authorized to sell a publisher’s products and services. While this took time and resources for publishers to adopt, advertisers were highly in favor of ads.txt as it helped verify the validity of sellers, resulting in a higher standard of internet fraud prevention. By November 2017, more than 44% of publishers were using ads.txt. Among the top 1,000 sites in the programmatic space, 57% hosted ads.txt files according to Pixalate. Major DSPs have even stopped buying inventory that doesn’t have an associated ads.txt file. 

The adtech ecosystem is a constantly-evolving space and in order to succeed at digital advertising,  it’s important to stay aware and adaptive to emerging trends. Coegi’s core processes and solutions are rooted within data and adtech so we are keen on staying up-to-date with digital trends and how they impact our work. Read below to find out more about what publishers and advertisers think about app-ads.txt.

The Rise of App-Ads.txt

Fast forward to 2019 and adtech companies are now discussing the adoption of app-ads.txt, anxiously waiting for IAB Tech Lab’s official release of app-ads.txt in the mobile app space. Similar to ads.txt for desktop devices, mobile app publishers can list authorized sellers and resellers of their inventory via mobile app-ads.txt while programmatic ad buyers can check these lists to make sure the suppliers claiming to offer this inventory is actually able to see the inventory. 

Just like the adoption of ads.txt for web servers, there are feelings of both apprehensiveness and support of app-ads.txt from the POV of publishers and advertisers. Here are points to consider from each side:


  • Publishers, developers and supply-side platforms sometimes face slower adoption rates due to technical obstacles and the time needed to create, implement and host app-ads.txt files.
  • Publishers have expressed the risk of losing out on ad revenue because if there’s one error in an app-ads.txt file or if certain demand sources are suddenly excluded, this could result in thousands of dollars of revenue loss per day.
  • With the rising presence of ad fraudsters, efforts by publishers to implement app-ads.txt may be thwarted despite best efforts.


  • Big players like Google, The Trade Desk, and Centro are just a few companies that have taken a strong stance in favor of app-ads.txt usage.
  • Fraud rates, especially those related to invalid traffic, are still high in the mobile app space. The purpose of app-ads.txt is to help ensure a cleaner ecosystem and have the same effect as ads.txt did for the desktop/browser world. 
  • Sophisticated invalid traffic rates doubled last year according to studies by DoubleVerify. The percentage of fraudulent apps also grew by 159% in 2018 solely to steal ad dollars. Having a verifiable list of allowed sellers and resellers with app-ads.txt can decrease fraud rates and help ease the minds of demand-side partners.

What Does this Mean Moving Forward?

What this means for all players is simple: a cleaner ecosystem and increased confidence in knowing that ad dollars are being spent efficiently in the mobile app environment. By keeping a firm stance on how ad dollars will be allocated, brands and their advertising partners can make sure publishers and app developers stay committed to maintaining high quality traffic standards. Publishers and app developers also need to have the support and direction to help resolve traffic quality and fraud issues. Having honest, open communication about these concerns and educating those who do not understand the purpose of ads.txt will help the fight against fraud.


For the latest industry updates, insights and more: subscribe to our weekly newsletter The Pulse.