AppNexus Updates

Update: Ads.txt Enforcement and Fraud Refunds

Blog Post
The AppNexus Team
Reading Time: ~2min

At a base level, digital advertising should be transparent, brand-safe, and fairly priced. Unfortunately, two of the biggest issues that advertisers face today are opacity in the programmatic supply chain and quality in the digital advertising marketplace. 

To bring resolution to these problems, AppNexus is making long-term investments to bring safety and transparency to the digital advertising ecosystem. Two key aspects of our commitment to transparency and safety for buyers are refunds on invalid traffic and stringent enforcement of ads.txt.

Refunds on invalid traffic 

Invalid traffic, while low on our platform due to proactive monitoring, is a legitimate concern for buyers and sellers of digital advertising.

Starting March 31, AppNexus is implementing new policies to streamline the refund process for buyers who have purchased invalid traffic on our platform. Buy­side clients who have purchased non­human traffic may submit a claim to AppNexus Business Support through the Customer Support Portal subject to the following conditions: 

  • Claims must be submitted for the previous month's activity within 10 days of the month’s close. For example, for March activity, a claim must be submitted by April 10th. Buyers should submit one claim covering the entire month's activity (this is an update to a previous version of this policy that stated the claim must be submitted within 30 calendar days of the incident).

  • The claim must include reporting from an approved third-party verification service. Third-party verifiers currently accredited to participate in the AppNexus rebate program are:
    • comScore
    • DBM
    • DoubleVerify
    • IAS
    • Buyers must provide the following data points in their third-party reports:
      • Placement ID
      • Seller member ID

      • Campaign ID

      • Line item ID

      • Total imps

      • Number of invalid imps

      • % of invalid imps

      • Reporting must be at a daily level

  • If buyers meet the above criteria, any seller(s) involved will be notified by email by the AppNexus team. The amount of the credit will then be withheld from the seller’s next pay cycle. Sellers can see this itemized in their seller statement.


End to end, these policies enforce accountability on our platform, so buyers and sellers can rest assured they are transacting on legitimate traffic and inventory.

Support for Ads.txt

AppNexus strives to be the most trusted, effective global marketplace for buying and selling advertising on the internet. As part of that commitment, we fully support industry initiatives that streamline the digital advertising ecosystem and bring transparency to the supply chain.

Ads.txt gives publishers a standardized way to publicly list all of their authorized programmatic partners in order to prevent unauthorized inventory sales. An early supporter of the initiative, AppNexus announced that it would automatically, and without exception, enforce publishers’ ads.txt files by disabling buying on unauthorized sellers through the AppNexus Programmable Platform (APP).

Now that a critical mass of publishers have adopted ads.txt—over 80% of the top 1000 domains available within the AppNexus marketplace have an ads.txt file—AppNexus disables buying through APP from parties that are not directly identified through the publisher’s ads.txt files as authorized resellers. Due to the scale of inventory in AppNexus’ marketplace, buyers have continued to hit goals with little change to how spend was allocated.

Enforcement of ads.txt furthers AppNexus’ measures to minimize domain spoofing and increase brand safety controls for our buyers. Combined with our established anti-fraud detection systems, ads.txt compliance further strengthens our core commitment to safety and transparency and provides a safe way for our buyers to purchase media from authentic sellers.