What is ads.txt?
Ads.txt is a specification created by the IAB (Internet Advertising Bureau) to help eliminate unauthorized selling of ad-monetizable publisher inventory (e.g., video content). Ads.txt stands for “Authorized Digital Sellers” and is a method for publishers to publicly declare which companies are authorized to sell their digital inventory.
Ads.txt is simply a plain text file that you host on any website where you monetize your video content with advertising. The ads.txt file specifies which advertisers are authorized to sell your video inventory for ad revenue. This helps reduce fraudulent selling of your inventory by unauthorized sellers. Ads.txt files should also be integrated with your ad servers and SSPs to specify which buyers can purchase your video inventory.
How does ads.txt work?
When you make your video inventory available for ad monetization, you’re authorizing ad exchanges to help find advertisers to purchase (make bids against) your inventory. These advertisers have no way of verifying who is authorized to sell your content; therefore scenarios could arise where an unscrupulous seller is intentionally trying to deceive sellers by mislabeling inventory to look like it’s coming from one of your domains, or perform some other similar kind of ad sales fraud.
Ads.txt helps eliminate this by allowing advertisers (the buyers) to independently check which sellers are authorized to sell your video inventory for ad monetization via your ads.txt files. If a seller does not appear on your ads.txt file, advertisers simply won’t purchase inventory from them, preventing these fraudulent sales from occurring and ensuring your domain and/or branding isn’t getting tarnished in the process.
To help illustrate this, see this diagram provided by the IAB:
- Your inventory is highlighted in green in the “Content owner” boxes.
- The advertiser bidding on ad space for your content is highlighted in blue.
- Advertisers can verify which sellers are authorized to sell your content for ad monetization by reviewing the ads.txt files you publish on your domains (or with your ad servers).
What does a sample ads.txt file look like?
Check out a few real world sample ads.txt files:
How do I set up ads.txt?
For any websites you own and operate directly, you’ll want to add an ads.txt file under the root domain. For example: https://www.example.com/ads.txt
Ads.txt files are simply plain text files that contain the following elements:
- Domain name of the advertising system (Required) - The canonical domain name of the SSP, Exchange, Header Wrapper, etc system that bidders connect to. This may be the operational domain of the system, if that is different than the parent corporate domain, to facilitate WHOIS and reverse IP lookups to establish clear ownership of the delegate system. Ideally your SSP or exchange publishes a document detailing what domain name to use.
- Publisher’s Account ID (Required) - The identifier associated with the seller or reseller account within the advertising system in the above field. This must contain the same value used in transactions (i.e. OpenRTB bid requests) in the field specified by the SSP/exchange. Typically, in OpenRTB, this is publisher.id. For OpenDirect it is typically the publisher’s organization ID.
- Type of Account/Relationship (Required) - An enumeration of the type of account. A value of ‘DIRECT’ indicates that the Publisher (content owner) directly controls the account indicated in the Account ID field on the system. This tends to mean a direct business contract between the Publisher and the advertising system. A value of ‘RESELLER’ indicates that the Publisher has authorized another entity to control the account indicated in field #2 and resell their ad space via the system in field #1. Other types may be added in the future. Note that this field should be treated as case insensitive when interpreting the data.
- Certification Authority ID (Optional) - An ID that uniquely identifies the advertising system within a certification authority (this ID maps to the entity listed in field #1). A current certification authority is the Trustworthy Accountability Group (aka TAG), and the TAGID would be included here
And ads.txt file will look similar to the following:
# Ads.txt file for example.com:
redadexchange.com, 12345, DIRECT, c997236a2<
bluessp.com, 9876, RESELLER, f345231
yellowadexchange.com, YZ231, DIRECT
greenexchange.com, 88327, RESELLER
goldssp.com, ABC928, RESELLER
Use the following resources to get more specific instructions for configuring your ads.txt files:
- For google DFP: https://www.youtube.com/watch?v=Obe8Napvpuo
- For all other SSPs: https://iabtechlab.com/~iabtec5/wp-content/uploads/2016/07/IABOpenRTBAds.txtSpecification_Version1_Final.pdf
Does my SSP support ads.txt?
More and more ad servers are coming on board with the ads.txt initiative! Please reach out to your ad provider and ask them if they support ads.txt. They should also be able to provide instructions on how to configure an ads.txt file to white label them to sell your publisher inventory on your behalf.
Was this article helpful?
Articles in this section
- Ad Tags Overview
- Ad Timings
- Ad Pods
- How to Use Ad Tag Macros
- Companion Ads
- Supported Ad Servers and SSPs
- How to Verify Ad Server / Ad SSP Integration with Zype
- Unlocking a Google Ad Manager Profile and Generating Feeds
- Use ads.txt to reduce fraudulent sales of your publisher inventory
- How to set up an ad fallback / waterfall using DFP Small Business