App Tracking Transparency (ATT)

Introduced by Apple in 2021, App Tracking Transparency (ATT) is a privacy feature that gives users greater control over their data. It requires apps to request permission from users before tracking their activity across other companies’ apps and websites for advertising purposes. ATT has been praised by privacy advocates and has had a significant impact on the digital advertising industry, though some developers have expressed concerns about the impact of ATT on their revenue streams.

This privacy-increasing guideline was introduced with the beta release of iOS 14.5, iPadOS 14.5, and tvOS 14.5, and continues in subsequent releases of Apple’s mobile and smart TV platforms. The AppTrackingTransparency framework shows users a popup asking for their permission to access their device’s unique identifier for tracking purposes.

As Apple highlights in their privacy policy and data use article:

Tracking refers to the act of linking user or device data collected from your app with user or device data collected from other companies’ apps, websites, or offline properties for targeted advertising or advertising measurement purposes. Tracking also refers to sharing user or device data with data brokers.

If people choose to opt out, advertisers and ad networks will not be able to see their IDFAs, a device identifier for advertisers. If people opt in, advertisers and ad networks will in fact see them. An IDFA is a unique identifier that allows companies to recognize a user’s device and track their activity across apps and websites. The goal of tracking an IDFA is to measure and analyze the performance of marketing campaigns.

You can check how many people opt in and opt out of App Tracking Transparency in Singular’s quarterly trends reports.

As a result of this Apple privacy policy, mobile marketers and advertisers need to plan how they will measure marketing effectiveness under this new tracking framework. Apple’s aforementioned privacy page highlights several examples of tracking that will be impacted by this change, including:

• Targeted display ads within an app based on data collected by third-party websites or apps
• Collecting and sharing a devices location or email with a data broker
• Collecting and sharing advertising IDs or other unique identifiers with third-party advertising networks for the purpose of retargeting
• Using third-party SDKs within an app that combines users data with data from other apps in order to measure advertising performance

Apple also specifies certain use cases that don’t fall under the definition of tracking and thus do not require user consent with the AppTrackingTransparency framework:

• When a user’s device data from an app is linked to third-party data but is kept on the device, and not sent off the device for the purpose of identifying either the user or device
• Sharing user data with a data broker for the sole purpose of mobile fraud prevention, detection, or security is allowed

It’s important to note that in the consent popup that requests permission with the AppTrackingTracking framework, you must include the reason that you’d like to track the user. This purpose string in the prompt is meant to explain to the user exactly how their data will be used to help them better understand what they’re opting in to.

Another change with the AppTrackingFramework is that users can turn on or off IDFA sharing on an app-by-app basis. Previously, users only had a single option to toggle their IDFA sharing preferences for all apps. Apple provides the following suggestion for users that have turned off tracking for your app:

If the user allows apps to request to track, but has turned tracking off for your app, you can ask the user to change their preference for your app by providing a shortcut to Settings where they can change the tracking permission.

What Apple has provided instead of IDFA-based ad measurement is SKAdNetwork, or SKAN. From our glossary entry on SKAN:

SKAN (StoreKit Ad Network, or SKAdNetwork) is a framework created by Apple for privacy-preserving mobile app install attribution. It aims to help measure conversion rates of app install campaigns without compromising users’ identities. The first widely usable version of SKAdNetwork was SKAN 3, which is still the most used.

The key to accurate measurement under ATT, or App Tracking Transparency, is extremely sophisticated use of the SKAN framework to maximize the privacy-safe ad performance data it enables.

SKAN is transitioning in iOS 18 to AAK, or AdAttributionKit, which is fully compatible with SKAdNetwork, Apple’s first privacy-preserving advertising measurement framework, but was built for an app ecosystem in which the iOS App Store, owned and operated by Apple, is not the only place to get apps for iPhones and iPads.

With ATT, marketers need to use SKAN to understand the impact of their advertising. (Transitioning, eventually to AAK.)

But there are some challenges:

• measurement fragmentation between SKAN, MMP tracking, Apple Search Ads (which does not use SKAN or AAK), and IDFA
• inaccurate measurement, thanks to privacy-oriented data censorship and signal degradation
• duplicated install counts across multiple methods
• limited post-install insights

Singular’s SKAN Advanced Analytics used advanced modeling and first-party data to enable accurate marketing measurement even without access to an IDFA. And our new iOS Unified Measurement takes that to the next level, boosting accuracy 31% and returning true organics, accurate CPIs, and long 35-day cohorts: all things that ATT and SKAN initially took away.

Unified Measurement deduplicates SKAN and traditional MMP attribution, and is not impacted by Privacy Thresholds in SKAN 3 or Crowd Anonymity in SKAN 4 or AAK. Unified Measurement takes data from multiple sources, including your own first-party data, the ad delivery and performance data from your ad networks, and SKAN/AAK postbacks to build out a comprehensive collective view of marketing performance and the impact of growth initiatives.

SKAN and AAK are an important part of a marketers’ data collection after ATT, or App Tracking Transparency. But they’re not all you have to rely on.