To begin with, ads.txt is a publicly accessible text file used by website publishers to publicly share a list of ad networks and supply-side platforms (SSPs) authorized to sell their ad inventory. app-ads.txt is the mobile marketing version of this, that lists ad networks participating in mobile in-app and OTT advertising. The purpose of these files is to prevent ad fraud and ensure a transparent advertising process. By releasing the list to the public, programmatic buyers are able to verify if the ad inventory they are trying to purchase is from a legitimate seller or a forgery.
First, before publishing an app, mobile app developers compile a list of ad networks and SSPs that are authorized to sell ad inventory on their app into an app-ads.txt file. Developers upload this file to their developer website and include the website’s URL on their app store listing’s database.
Once the app-ads.txt files are placed, ad buyers and advertisers can crawl the database to retrieve the URL and decode it into an app-ads.txt file listing all authorized vendors. They can then use this information to check if the ad networks and SSPs that placed bid requests are acceptable or not.
app-ads.txt has become a fundamental tool in the advertising ecosystem today, as it solves the impending issues of ad fraud. Counterfeiting inventories and spoofing have become prevalent, and identifying such cases of fraud has always been a challenging task to solve. app-ads.txt offers an effective solution, minimizing the chances of encountering numerous ad fraud issues. Below are some of the main types of fraudulent activities that app-ads.txt prevents:
Illegal inventory arbitrage is when third-party vendors negotiate with publishers to buy ad inventory at a lower price, repackage, and resell it at a higher price. This results in a loss of revenue for publishers, while advertisers are overcharged with fraudulent prices. By indicating the authorized vendors allowed to sell inventory, advertisers are able to cross-reference the list for verification before making a purchase.
Domain spoofing is one of the most commonly occurring fraud activities in the mobile advertising space. This is a technique where fraudsters impersonate a legitimate app developer and trick advertisers into thinking they are buying from a verified source, when in fact, dummy apps or apps that would have otherwise been blacklisted are selling counterfeited inventory. Using the list of authorized sellers provided by app-ads.txt files, buyers can make sure they aren’t being misled into these fake transactions.
Overall, the implementation of app-ads.txt has offered more transparency and security in the mobile advertising landscape, benefiting both advertisers and publishers and ensuring a smooth trading process for all. Today, app-ads.txt has become an industry-standard tool for both websites and mobile apps, and top app store platforms like Google Play Store and Apple App Store have adopted it into their operational systems.