The ads.txt (Authorized Digital Sellers) is not just a file but rather a kind of business card that you hand over to the public. Its absence is not only a technical shortcoming but can also be seen by others as a lack of willingness to cooperate and professionalism. For advertisers, it is the foundation of trust – if the ads.txt is not placed in your root directory, it may affect not only your campaign revenue but also how the market perceives you.

What does ads.txt contain?

Each line contains the details of an authorized advertising partner.

1. The domain name of the advertising platform
2. Publisher ID – the publisher’s identifier on the given platform
3. Type of relationship – DIRECT (direct) or RESELLER (reseller)
4. Certification code – optional, a code provided by the SSP

What does it reveal to advertisers?

• Through which platforms the ad inventory is being sold.
• Who the official, approved partners are.
• Whether the relationship is direct or through a reseller.
• Whether the information matches the data found in the sellers.json file.

How can you search for a specific advertiser or partner platform in it?

Since ads.txt is a plain text file, you can quickly search it by domain name or Publisher ID using any browser or text editor’s search function (e.g., Ctrl + F).

What happens if there is no ads.txt?

• Many advertisers or SSPs simply exclude websites that do not have an ads.txt file.
• Not using this basic tool may indicate that you are not concerned with the advertising security of your site.
• To an outsider (e.g., an agency or programmatic partner), its absence signals a lack of professionalism.

What can you do to avoid losing trust?

1. Create an ads.txt file in your website’s root directory (e.g., example.com/ads.txt).
2. Request the necessary lines from your partners and place them in the file.
3. Update it regularly, checking its content at least once a year.
4. Communicate that you are using it! Transparency is valuable.

Ads.txt is not only a technical requirement but also a tool for building trust. Just as a business card speaks about you at the first meeting, ads.txt sends a message to advertisers – that you are a transparent, reliable partner worth working with.