In order to identify unique users, Google created ‘GAID’ (Stands for - Google Advertising ID), And Apple created ‘IDFA’ (Stands for - Identifier for advertising).
While some of our tracking solution partners do offer dedicated macros to support GAID/IDFA targeting, it’s important to understand that users are able to opt out of tracking from advertisers in their device settings.
If a user chooses to opt out of tracking from advertisers, the GIAD/IDFA value would not return, even if the macro was implemented in the tracking link.
Also, some of the publishers do not have access to this identifier and can not pass it on in the tracking link.
