October 15, 2019

At the end of last year, we announced the adoption of ads.txt across the Integrated Advertising Platform, including Adform’s Demand Side Platform and Supply Side Platform. Now, we are happy to announce the adoption of the app-ads.txt standard as our latest investment into safer supply while focusing on the mobile in-app environment.

Effective October 15, Adform will start to actively filter unauthorized sellers for app publishers who have published an app-ads.txt file. This will apply to inventory sourced from all connected Supply Side Platforms.

What is App-Ads.txt?

Earlier this year the IAB announced the final version of the app-ads.txt specifications – It is an extension of the original ads.txt standard for the declaration of authorized digital sellers. Building on the mission of the ads.txt standard, app-ads.txt has been designed to bring further transparency to the app-based side of the programmatic advertising ecosystem.

As noted by the IAB, “By creating a public record of Authorized Digital Sellers, ads.txt together with app-ads.txt will create greater transparency in the inventory supply chain and give publishers control over their inventory in the market, making it harder for bad actors to profit from selling counterfeit inventory across the ecosystem. As publishers adopt app-ads.txt, buyers will be able to more easily identify the Authorized Digital Sellers for a participating mobile and OTT publisher, allowing brands to have confidence they are buying authentic publisher inventory.”

The record serves as a key tool in identifying, tracking, and preventing inventory fraud and counterfeiting. These nefarious acts undermine the publisher’s brand value while depriving them of valid impressions and simultaneously results in advertisers potentially paying a premium for fake or misleading impressions.

Ads.txt and app-ads.txt are fundamentally about bringing enhanced transparency to the supply path, helping flag and eliminate domain spoofing, unauthorized resellers, and other fraudulent or deceptive business practices. This in turn delivers immediate advantages for advertisers, publishers and transparency-focused tech providers like Adform.


Market adoption of app-ads.txt as observed by monitoring via the Adform DSP is quite low, only reaching 11% across the two dominant app stores. However, the 11% of publishers who have adopted app-ads.txt generate 60% of all in-app ad requests. When compared to ads.txt, there are more challenges for the publishers to address with the implementation of app-ads.txt which has likely added to delayed adoption.  Further, the sophistication and complexity of the app-ecosystem has meant that almost half of the requests where app-ads.txt has been implemented contain errors leading to unauthorized requests (see Figure 1 below).


Figure 1: Daily distribution of requests from publishers with app-ads.txt implemented including authorized requests.

Figure 1: Daily distribution of requests from publishers with app-ads.txt implemented including authorized requests.

These challenges might not be purely on the publisher side, but rather stem from the exchanges that they have onboarded and the complex supply paths they have created in order to monetize publishers’ app inventory. Due to the early nature of app-ads.txt adoption, the amount of unauthorized supply still varies from exchange to exchange. To help reduce this variance and improve overall quality, Adform is working closely with our trusted supply partners to further support successful app-ads.txt adoption.

An Ever Improving Path to Safer Supply

CTV/OTT is not currently included in this release of app-ads.txt but is slated for addition in future releases. Introduction of app-ads.txt and full support will also follow on the Adform SSP in coming months. This will exclude requests from sellers not listed in app-ads.txt file in an effort to further clean up the supply path. Support of app-ads.txt within our SSP will provide an additional filtering layer to prospective buyers purchasing inventory, even if the external DSPs currently lack app-ads.txt implementation of their own.

Our Commitment to Keeping You Safe

The use of ads.txt and app-ads.txt data is part of our multi-faceted SPO and anti-fraud strategy dedicated to delivering added peace of mind, a clearer supply path, and enhanced control to advertisers and publishers.  They align with our ongoing strategy to champion new industry initiatives such as sellers.json and supply chain object.  In addition to being one of the only DSPs to secure MRC Accreditation for Display and Video impression and viewability measurement, Adform is one of the first advertising technology providers to secure TAG’s Certified Against Fraud seal via independent audit. The combination of these leading industry certifications pairs with Bearskin, Adform’s internal anti-fraud solution to raise the bar for the industry.