For Advertisers- Anti Fraud Advertising Solution- Ads.txt - Easy explanation by Sarang Kinjavdekar

Every advertiser wants his Ad to be Viewable, Fraud free and in a Brand safe environments. Today, I will talk about a very effective solution which is focused on increasing transparency and reducing fraudulent activity in the digital advertising ecosystem.

The current digital ecosystem is extremely chaotic with Agencies, Publishers, DMPs, Agency Trade Desks, Ad Networks etc and before the introduction of ads.txt , it was nearly impossible to check the validity of the inventory they purchase. 

Lets start with the basics first.

What is ads.txt ?

It is an IAB-approved text file that aims to prevent unauthorized inventory sales. The ads.txt file is a list of authorised digital sellers (ADS) that are authorised to resell a website’s ad inventory.

What Problem does ads.txt solves?

Is  specifically focuses on preventing the sale of counterfeit inventory. It is basically the latest advancement in Ant Fraud Technology. Ads.txt helps to solve this problem by indicating who the authorized resellers of a publisher’s inventory are.

As per Mediamath

When an advertiser buys media programmatically, they rely on the fact that the URLs they purchase were legitimately sold by those publishers. The problem is, there is currently no way for a buyer to confirm who is responsible for selling those impressions across exchanges, and there are many different scenarios when the URL passed may not be an accurate representation of what the impression actually is or who is selling it. While every impression already includes publisher information from the OpenRTB protocol, including the page URL and Publisher.ID, there is no record or information confirming who owns each Publisher.ID, nor any way to confirm the validity of the information sent in the RTB bid request, leaving the door open to counterfeit inventory.

How  does ads.txt is helping Advertisers?

It gives Advertisers/Buyers more confidence in the ads they purchase making sure that there is no Fraudulent activity involved in the purchase path

What is the format of ads.txt and which websites can use it?

Any website can use it and the files must declare:-  (i) Domain name of the advertising system or ad exchange (ii) Publisher account ID (iii) Type of relationship (iv)  Type of inventory

How does ads.txt looks like?

Example- aps.amazon.com, 3713, DIRECT #display

How does ads.txt looks works?

Publishers places an ads. text file on their web servers that lists all of the companies that are authorized to sell the publishers’ inventory. 

Now you might be thinking what happens on other programmatic platofrms? Well, the process is exactly the same. Programmatic platforms also integrate ads.txt files,  this is needed to confirm which publishers’ inventory they are authorized to sell. 

So an Advertiser can check the inventory and the fraud status by checking the ads.txt file. This is usually done by Bidders which check the  a legitimate connection between the exchange and publisher


This is how it works as per IAB

Ads.txt works by creating a publicly accessible record of authorized digital sellers for publisher inventory that programmatic buyers can index and reference if they wish to purchase inventory from authorized sellers. First, participating publishers must post their list of authorized sellers to their domain. Programmatic buyers can then crawl the web for publisher ads.txt files to create a list of authorized sellers for each participating publisher. Then programmatic buyers can create a filter to match their ads.txt list against the data provided in the OpenRTB bid request.

How does Buyers use ads.txt ?

Lets say Buyer has list of all the Domains they need to purchase inventory from, they can then crawl the web to generate a record of all Authorized Digital Sellers for the particular Domains they are interested in.

As soon as the bid request is received at Buyer's end, they can verify the information using the placeholders in Ads.txt and verify if they are purchasing authorized inventory or not.


I hope you enjoyed reading this article!

Thanks for reading!

Sarang Kinjavdekar