What Happened to SKAN 5? Breaking down Apple’s AdAttributionKit

If you’re a mobile marketer following Apple’s privacy changes, you’ll know it’s been quite the journey. When Apple announced SKAdNetwork (SKAN) 5 at WWDC 2023, its re-engagement capabilities—specifically, its ability to offer insights into down-funnel activity for users targeted by UA campaigns who already have an app installed—made many advertisers optimistic about the added benefits over SKAN 4.

But at WWDC 2024, SKAN 5 was a no-show. Instead, Apple rolled out AdAttributionKit (AAK), which will be available from iOS 17.4 onwards (with further features slated for release in iOS 18). So, what gives?

What is Apple’s AdAttributionKit?

Apple describes AdAttributionKit as its “new” attribution framework that enables broader ad attribution capabilities. It’s designed to strengthen privacy protections in the Apple App Store and other marketplaces while also addressing regulatory requirements, especially in relation to Apple’s interpretation of the EU’s Digital Markets Act (DMA). If you look closer, however, you can argue that AdAttributionKit is just a rebrand of SKAN 5.

Both share a similar framework with three cryptographically signed postbacks, 64 conversion values, and near-identical privacy features. Given that SKAN 4.0 has struggled with uptake, with our 2024 App Marketer Survey finding that 35% of mobile marketers are still unfamiliar, it’s hardly surprising that Apple would want to start afresh. We imagine the various teething problems SKAN 4 has struggled with since its release, including a notable bug that caused conversion value issues, also factored into the decision.

The differences between AdAttributionKit and SKAdNetwork

While they may have many similarities, mobile marketers should be aware of some notable differences between the AAK and SKAN.

Designed for interoperability

Apple designed AAK and SKAN to be interoperable. If an ad served in a publisher app uses SKAN to serve an impression, the postback returned by Apple will be in SKAN format. If an ad served in a publisher app uses AAK to serve an impression, the postback returned by Apple will be in AAK format. Your MMP and/or demand partner must correctly support the postback processing and aggregating reporting.

Alternative app store coverage

The biggest difference is that AAK works with the App Store and alternative app marketplaces, while SKAN is only compatible with the former. The new framework also supports a broader range of ad formats than SKAN, including custom click ads, view-through ads, and various overlay styles (such as banner ads and full-screen listings).

For mobile marketers, this means they can expand their reach and acquire users from a broader range of platforms using more ad formats, enhancing their overall user acquisition strategy.

Developer mode

One of the major complaints about SKAN is its overall complexity, making it sometimes challenging to run tests. Apple has taken that to heart, as AAK introduces a developer mode.

Once this mode has been activated, time randomization is removed from the system, and conversion windows are shortened. This means conversion value update testing can occur in all three windows in a “test-friendly timeframe.” This mode also enhances debugging by providing real-time data and debug information, allowing developers to identify and fix attribution issues quickly.

AdAttributionKit also incorporates stricter ad fraud prevention measures, such as requiring ads to be displayed in the foreground and limiting the use of timers to end impressions prematurely.

The return of re-engagement

One of the uncertainties when Apple announced AdAttributionKit was what this meant for the announced re-engagement features for SKAN 5. The good news is that everything initially promised for SKAN 5 has carried over into the new AAK framework.

With AdAttributionKit, demand partners can designate ads for re-engagement by setting the “eligible-for-re-engagement” parameter to “true” in the impression JSON (JavaScript Object Notation). When a user with the advertised app already installed clicks on such an ad, a universal link will open the app and direct the user to the specified in-app location. The ad will direct the user to the appropriate app store if the app isn’t installed.

Should you adopt Apple’s AdAttributionKit?

While the benefits mentioned above might look tempting, we’d argue that for most mobile marketers, there’s little reason for advertisers to rush out and adopt this new framework at the time of writing.

While leveraging alternative app marketplaces would be a great advantage, only some stores have built up a significant audience. Likewise, while enhanced engagement features are useful, they aren’t crucial to most UA strategies.

That said, we expect AdAttributionKit improvements in the future. App marketers should continue to research and stay updated with any changes so they’re not caught off-guard if AdAttributionKit becomes standard for iOS mobile advertising.

We’ll continue to provide these updates on the Liftoff blog. And if you decide to make the transition now, we’re here to help you navigate the process and make it as straightforward as possible.

If you’d like to learn more about Apple’s attribution frameworks, check out our blog post on SKAdNetwork and its impact on mobile marketing.