Google Publisher Tag allows you to generate tags with "passback" functionality. These tags can be used in any situation where an ad request to a third party should ultimately be filled by an ad trafficked in your own Ad Manager network.
Use passback tags to traffic remnant or fallback line items
Passback tags can be used when a third-party server doesn't have an ad to serve or when an ad doesn't meet the minimum CPM/floor price agreed upon with the third party. In these cases, the third-party server instead serves the GPT passback tag, which returns a house ad or other remnant ad from your own Ad Manager network.
Use passback tags to serve ads on another publisher's website
Passback tags can be used to serve ads from your network to another publisher's website. In these cases, the GPT passback tag would be trafficked by the other publisher and would return an ad from your own Ad Manager network.
Use passback tags to serve video ads
To create video passbacks, use a standard video tag to pass back from a third party to Ad Manager.
You can build this tag manually or using the Ad Manager video tag generator.
Create GPT passback tags
Passbacks use the Google Publisher Tag API with no additional functions needed. The GPT snippet must be rendered in an iframe to prevent the passback from inheriting any page-level settings from any other GPT instance running on the publisher page.
Customize your passback tags by adding click tracking and key-values.
Read the Developer Documentation
GPT Passback API
If you want to use a passback from a 3rd party ad server, use a standard Google Publisher Tag written into an iframe.
We recommend replacing passback functions, definePassback() and defineOutOfPagePassback(), as this code may break or cause performance problems.
