SKAN 4.0: What Publishers Need To Know

Updated April 28, 2023 

In their 2022 annual Worldwide Developers Conference (WWDC), Apple announced a new version of SKAdNetwork (4.0), which aims to introduce significant changes for app marketers and ad networks to measure more data on app installs while maintaining user privacy.  After much industry speculation, SKAN 4.0 was released on October 24, 2022 along with iOS 16.1.

What’s new with SKAdNetwork (SKAN) 4.0? 

Designed to answer some of the gaps observed in the previous versions and provide more insights to app advertisers, SKAN 4.0 will introduce 4 key new features. Here’s a summary of what we know: 

Hierarchical source identifiers

The campaign identifier field has been renamed as source identifier and will now include up to four digits in the postback vs two previously to allow advertisers to assign the meaning of the digits in a more flexible way. The number of digits being passed in the postback (2, 3 or 4) will depend on the crowd anonymity, which is a privacy threshold determined through the count of installs in a campaign and is define as low, medium, or high. The higher the count, the higher is the anonymity, and the more data can be sent back.  

Hierarchical conversion values

The conversion value field will now introduce 2 conversion values which will be passed depending on the crowd anonymity:  

• Fine-grained value, the same 6-bit value that is used for conversion values today and will be returned in the postback in case of high privacy threshold level.   
• Coarse-grained, that can be only assume one of three values – low, medium, high and will be returned in the postback in case of medium privacy threshold level. 

Multiple conversion windows 

A much-awaited feature, SKAN 4.0 will now enable app marketers to measure re-engagement through three postbacks, as opposed to only one previously. The postbacks are tied to 3 specific time windows:  

1. 0 – 2 days 
2. 3 – 7 days 
3. 8 – 35 days 

Only the first postback will receive fine-grained conversion values, postbacks 2 and 3 will receive coarse-grained values.  

Web to app attribution

For publishers who have hybrid inventory across app and web environments, the previous SKAN versions were limited to app and were not supporting cross-channel attribution. The new version will now support click attributions for ads shown in Safari that direct the user to an app’s App Store product page. This improvement will be greatly valued on specific app categories, and in some heavy web markets like Australia and Japan where mobile web publishers will now have a chance to participate in the SKAN ecosystem and increase their revenue. 

What are the benefits for publishers? 

Every app developer is also an app marketer. Ultimately SKAdNetwork allows them to measure their return on ad spend and marketing strategies. 

Whilst it can be difficult to measure direct revenue increase linked to SKAN adoption, here’s why app developers should care about adopting SKAN and its latest 4.0 version when it comes to monetizing: 

• Capturing advertising budgets – Some advertisers and demand platforms are only buying on SKAN-enabled inventory, so app developers not supporting SKAN may lose out on the revenue opportunity.  
• Maintaining attribution in a post-ATT world – We observed that opt-in rates have remained stable at 31% in the last few months. This means that 69% of users don’t have an IDFA and it is not possible to enable deterministic attribution on these users. Therefore, it is imperative for app developers to support SKAdNetwork to keep providing value to advertisers through a privacy-safe probabilistic attribution model in a world where mobile identifiers are fading away. 
• Benefit from iOS consumers spend – Whilst the worldwide iOS mobile operating system market share doesn’t dominate, it varies by region and market (57% in the US), but more importantly iOS represents the majority of consumer spend worldwide - $84B vs $48B on Android in 2021. In other terms, iOS users spend more, and advertisers will want to acquire these users. 
• Diversify the ecosystem – In their latest Mobile App Advertising Benchmark Report, Appsumer shared that Apple Search Ads (aka ASA), a user acquisition channel that runs campaigns directly within the App Store, has gained strong momentum on advertiser adoption (YoY 94%) and share of wallet (15%). This further builds on ad spend heading into walled gardens and the high reliance on them - and which specifically impacts the ad revenue growth of small and medium app developers.  

At InMobi, 95% of our app developers' customers had adopted SKAdNetwork 2.2 in Q4 2022. We’re now excited to announce that the InMobi Exchange supports SKAN 4.0 on the latest InMobi iOS SDK - Swift (version 10.5.5) and Objective-C (version SDK 10.1.3).   

To adopt or upgrade to SKAN 4.0, download our latest iOS SDK or adapter and be sure to add all the SKAN IDs to your app’s info.plist.