What is an Advertising ID (IDFA and GAID)?

An advertising ID is a unique, anonymized user identifier. It consists of a mixture of alphabets and numbers that are assigned to a device such as a phone, computer or a tablet.

What are the types of advertising IDs?

The two most known types of advertising IDs are:

1. Apple's Identifier for Advertisers (IDFA)
2. Google's Advertising Identifier (GAID)

What are advertising IDs used for?

Advertising IDs help advertisers track user-level activity and data so they can deliver tailored advertisements. If the channel in question has allowed IDFA or GAID tracking, and if the advertiser has set up user tracking successfully, these advertising IDs can give advertisers a lot of information about users’ in-app behavior without revealing their personal information. Advertisers can then use that information to optimize their campaigns and scale their businesses.

What are the limitations of advertising IDs in the post-IDFA world?

The introduction of App Tracking Transparency (ATT)

Since the implementation of privacy changes and App tracking transparency (ATT)—an iOS pop up that asks users for consent to be tracked—more and more users are choosing to opt out of targeted advertisements.

The best strategy to follow when requesting users’ IDFA and increasing the chances of them accepting the prompt is the one suggested by Kevin Bravo. Since Apple allows developers to place the ATT native pop up when they want, but limits them to only show it once per device, developers usually place custom pop ups strategically within their app. This could look something like a custom message stating that opting in to ad tracking could help users with their overall ads experience. Such a message is followed by a ‘next’ call-to-action that leads to the native ATT pop up. For those users who accept the ATT, developers receive their advertising ID and are able to track their activity. For those who reject, developers and ad networks will not have access to their advertising ID and will receive ‘0000-0000-0000-0000’ in its place.

SKAdNetwork: The new attribution framework

SKAdNetwork is the privacy-centric attribution framework provided by Apple. This model allows developers and ad networks to continue tracking app installs while maintaining user privacy.

To learn more about SKAdNetwork 4.0, and how advertisers can use it check out this article.