ads.txt/ performance/ adtech myths

Blog by the WhizzCo Team


Is the connection between ads.txt lines and performance a myth?


Is it essential for publishers to limit ads.txt lines to improve ad monetization? 

Publishers frequently tell us that introducing additional ads.txt lines is a genuine concern, but our understanding at WhizzCo is that the length or number of lines in an ads.txt file does not negatively impact performance.

We asked the Reddit AdOps community and the answer wasn’t as straightforward. This is how 77 people responded:

ads.txt survey

While over half responded there is no correlation between the number of ads.txt lines and performance, several respondents qualified their answers.

For example, @HB-Adops commented that a key option was not included in the poll, “Yes but there is no magic number.”

He further explained, “Even 1000 lines could be fine. You should know the SSPs you are allowing to bid and which one is a direct buyer and which is a reseller and if you are giving the opportunity to some company to buy ads cheaper on your website due to different entries.”

@cougar16 also commented that “This is a more complex answer than the vote allows, and people will have strong opinions…The amount of lines really depends on your business model and the number of ad unit variations you have on your property. For instance, you may have 10 buyers for video inventory, 10 buyers for native, and 10 for display and they could all be different entries you could have ones specific to desktop vs mobile web as well. So it’s unique to each publisher’s situation.”

What do you think? Should publishers limit ads.txt lines?

Having more advertising partners (more ads.txt lines) who can access your inventory should improve performance, because you are opening the door to more advertisers.

Our experience shows that there is no predefined threshold for the number of ads.txt lines. Publishers should focus on accurately listing their authorized sellers and maintaining the file’s integrity rather than worrying about the specific number of lines.




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