What we learned about programmatic in Poland from studying the ads.txt files

In the past 5 months we published our header bidding market analyses of a few CEE markets – PolandBulgaria and Romania. In addition, on November 7th thanks to IAB Poland we had a chance to present our research comparing  Polish programmatic market to more mature Western markets (US, UK , Germany) as well as emerging CEE ones at IAB How To Programmatic conference. This time we would like to go a bit deeper and present our analysis of ads.txt files.


If you are a publisher and would like to sell your inventory programmatically, you need to have ads.txt implemented. Full stop. Ads.txt is an IAB initiative aimed at improving transparency in programmatic advertising and give publishers control over to whom their inventory is sold. As a verification tool, it also ensures buyers they’re paying for authentic publisher inventory.

Since ads.txt emerged in late 2017, it has become a widely adopted industry standard. That is why we made an assumption, that content of ads.txt reflects a general SSP’s popularity among publishers. Certainly, we are aware that some ads.txt entries might be outdated or inactive. Also, growing popularity of server-to-server connections between SSPs (i.a. Google Open Bidding, Smart, etc.) often leads to a situation where working with just one SSP means a publisher opens their inventory to multiple platforms. We observe it at Waytogrow too. Although average number of active SSPs is less than ten, our ads.txt entry consists of more than 40 lines. In case a publisher works with a few monetization partners, ads.txt file might be really massive.


Ads.txt files are publicly available and crawlable by exchanges, supply-side platforms, other buyers and third-party vendors. We compiled the top 1200 Gemius/PBI survey domains in Poland and built an in-house crawler in order to automatically scan these websites against ads.txt files. What have to emphasize, though, is that we focused only on Polish publishers, meaning that we manually removed international websites, for example Instagram, Accuweather, Yahoo, Linkedin, from the list.

As a first step, we identified 179 different platforms listed across all ads.txt files we analyzed. Then we checked whether a given platform (meaning SSP or other type of buyer) is included in publishers ads.txt files. As we wanted to avoid biased results stemming from the fact that some SSPs appear in ads.txt more than once, we did not calculate how many times it was, we just checked if an SSP is there or not.


  • The number of analyzed domains: 1200 sites based on Gemius/PBI survey.
  • The number of domains having ads.txt implemented: 537
  • The number of Polish domains having ads.txt implemented: 396

Below you can find the list of most popular SSPs based on the number of publishers’ ads.txt files a given SSP is listed. The top 5 platforms are Google, Rubicon Project, OpenX, Appnexus (Xandr) and Pubmatic.

Diagram for post
The number of publishers

But we noticed that some SSPs are much more popular among mid-size and long tail publishers, so we decided to assess their overall popularity based on the number of page views reported by Megapanel. As can be seen below, the top 10 platforms are exactly the same, also top 3 don’t change at all, but there are some fluctuations among positions 4-8.

Digram for post
The number of page views

There are also some additional insights we gained from this analysis we would like to share in this blog entry:

  • The average number of entries in ads.txt files is 31
  • Among 396 ads.txt files we analyzed, Google is not present only in 1
  • The most robust ads.txt we analyzed consists of 1809 entries
  • On the other hand the shortest one only includes 1 line
  • There are 179 different platforms/buyers listed in Polish publishers’ ads.txt


While this research is not free from some flaws, we strongly believe one can make some interesting insights based on it. According to our observations, as programmatic market is maturing in Poland, publishers work with multiple technologies in order to efficiently monetize their inventory. The rise of prebid.js, proprietary wrappers and server-side solutions only contributed to the diversity of this ecosystem and the list of 179 identified technologies/buyers only proves it.

Still there are a few platforms that seem to enjoy to biggest popularity among publishers, and this are Google, Rubicon Project, OpenX. The other pretty strong ones are Appnexus (Xandr), Smart and Pubmatic. So, as always, there is a limited group of key players and a long list of not that widely adopted, but still valuable technologies.

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