Fighting Ad Fraud

If digital transparency, authorised online inventory resellers and limited counterfeit ad profiteering sounds like a good idea, a text file could be just what the doctor ordered.

The Adx.txt initiative was released in May 2017 and allows advertisers to spend those important marketing budgets on authorised supply platforms. The IAB Tech Lab developed Ads.txt to assist publishers in the fight against ad fraud and to receive the revenue owed to them and increase market transparency.


What is ads.txt?


Ads.txt is an acronym for Authorized Digital Sellers. This piece of technology has been introduced by the IAB in an effort to eliminate the ability to profit from counterfeit or spoofed inventory in the open digital advertising ecosystem supply chain. Ads.txt allows publishers and content owners the ability to authorise and publicly declare who is allowed to sell their inventory.


Why is it necessary?


Ads.txt gives publishers the ability to control who gets to sell their inventory legitimately. This creates transparency in the market and thus limits the ability for digital criminals to profit off their inventory. Fraudsters have been getting really good at spoofing domains and this has resulted in an increase in “fake news” articles and ads as well as revenue being paid to illegitimate resellers. The adoption of Ads.txt assists in creating a fairer market in that advertisers will be sure that their marketing budgets are being spent on legitimate sites. It also ensures that publishers are earning the revenue they work so hard to get.


How does Ads.txt work?


  1. Publishers include a text file on their web servers which has a list of all authorised digital sellers or DSP’s who are authorised to sell the publishers ad space legitimately.
  2. Programmatic platforms (sellers) integrate the ads.txt files which confirms which publishers inventory they are authorized to sell.

Buyers (advertisers) are able to check whether they are buying from an authorized seller.


Who is currently using adx.txt?


Some examples of popular international publishers who have implemented ads.txt:



Which Ad exchanges are plugged into Ads.txt inventory? (Pixalate: 2017)

Ads.txt inventory


So how can you find out if a publisher has adopted ads.txt and which DSP’s are authorized to resell?


  • Type the website url followed by /ads.txt for example


Authorised DSP resellers

Here you can see that,, Rubicon Project and Outbrain are all authorized and have a relationship with ESPN.


Why is this relevant?
  • Unauthorised sellers of online inventory hurt publishers not just in terms of revenue, but also because advertisers may not return to run future campaigns.
  • Ads.txt does not promise to erase fraudulent activities but aims to assist in limiting the chances of it happening. Having a public register of all legitimate sellers and buyers and checking that frequently will mean spoofed domains have less chance of survival.
  • Ads.txt tries to limit fraud, however it can only work if buyers check for legitimacy and if publishers adopt the text file. The buyer has to manually check if the exchange is legitimate.
  •  There is a real benefit in educating publishers on this piece of tech as it mitigates against revenue losses.


The state of Ads.txt adoption?


Adoption rate amongst global publishers has been steadily increasing. According to Adopsinsider, adoption rate has grown from 13% in September 2017 to 44% in October 2017. Perhaps one of the biggest contributors to this is Google Doubleclick Bid Manager’s announcement that they would stop buying unauthorized supply paths by the end of October.


Ads.txt adoption


Where is South Africa with Ads.txt adoption?


Adoption from a South African context mimics the slow adoption globally. At the time this article was written six of the top twenty publishers (Effective Measure,2017) in the country had Ads.txt files implemented on their sites. That is only 30% of the country’s top publishers. This means that popular sites who receive a chunk of the digital ad spend could be victims of domain spoofing and perhaps worse; advertisers making use of those channels wouldn’t be getting their money’s worth. EWN, Sharenet and iAfrica, who are part of the 365 Digital stable are some of the publishers leading this movement in South Africa. We hope to see the more publishers get on board the fight against ad fraud and contribute towards a digitally transparent and fair ecosystem

365 Digital offers publisher’s solutions like these and ensures new developments and trends are highlighted in order to keep publishers ahead of the curve and in touch with the martech industry.



  • Effective Measure

Effective Measure

  • IAB Tech Lab

About ads.txt

Ads.txt – Authorized Digital Sellers

  •  Digiday

WTF is ads.txt?

  • Pixalate Blog

  • ClearCode

  • Adopsinsider

State of Ads.txt Adoption

Article by: Oreeditse Gill