Blog Unlocking the strategic potential of SKA...

Unlocking the strategic potential of SKAdNetwork 4.0’s new postbacks

Tiahn Wetzler, Director, Content & Insights, Adjust, Nov 22, 2022.

Released in October alongside iOS 16.1, Apple’s SKAdNetwork 4 (SKAN 4) comes with a lot of promising features for mobile app marketers. With a swathe of new opportunities to gain more data and increased insights into campaign performance on iOS devices, there’s a lot to be excited about, however, these new features also come with increased complexity. We’ve also just released our SKAN 4-ready SDK, along with what we’re calling The 4.0 milestones of SKAN 4, to help you get strategically prepped and ready for industry-wide adoption over the coming months.

Today, we’re digging into SKAN 4’s postbacks (there are now three!), looking at what’s changed, how they now work, and how you can make the most of the new system to create improved user experiences and drive sustained growth via your iOS campaigns in 2023.

SKAN 4’s three postbacks: What you get and when

Up until now, and when working with SKAN 3, developers only receive one postback containing information from the first 24-hours post-install. With SKAN 4, there’s more flexibility or wriggle room. Instead of one 24-hour postback window with a 24 hour timer that was extended every time a conversion value update was triggered, there are three measurement windows and three postbacks, or what Apple refers to as multiple conversions. The first postback measurement window is now 0-2 days instead of 24 hours, and the new second and third windows span 3-7 days and 8-35 days, respectively. That’s a lot of additional time to extract data and information from, but it’s a little more complex than it first looks. The postback timer, or the timeframe in which the developer receives the postback, has also been increased. Before SKAN 4 this was a maximum of 24 hours, now the timer for the first postback can be up to 48 hours, and for postbacks two and three, it can take up to 144 hours (6 days).

Apple has, however, also introduced lockWindow, which gives the option to apply a lock at a specific point within each window. This lock then cuts off the rest of the window and finalizes the postback with the most up-to-date conversion value at that point, and then begins the postback-return/attribution timer. This means that, for example, if all of the events you’re measuring occur before day 5, there’s no point waiting until day 7 to start the postback timer. Instead, you can apply the lock at day 5 and set the random 24-144 hour timer to start then, saving yourself two extra days of waiting. When it comes to applying the lock, it’s important to keep what we’re calling the measurement gap in mind. For example, if you apply the lock 10 hours into Postback 1, you will still have to wait the remaining 62 hours for Postback 2’s window to start, meaning you will not receive any SKAN info for these 62 hours.

Below we see how Apple has visualized the windows and the postbacks, with an example of lockWindow applied at around day 5 for Postback 2. Note that you can apply a lock in each window and that it can be different for each.

Let’s dive into each of the postbacks.

Postback 1: This window is now 0-2 days instead of 24 hours. Apple has introduced ‘fine’ and ‘coarse’ grain conversion values, and it’s only possible to receive ‘fine’ values (the same as the conversion values we’ve been working with up until SKAN 3) in Postback 1. You’ll receive a fine value if privacy threshold requirements are met, if they’re not, you might then receive a coarse grain value—and while this is less insightful, it’s better than the dreaded null.
Pro: Longer window for measurement, possibility of coarse grain conversion values which could decrease the percentage of null values.
Con: Longer attribution timer (up to 48 hours) meaning it can take longer to get data.
Note: With the new crowd anonymity tiers, campaigns with lower volume may have the chance of receiving coarse grain values however, if they only reach Tier 0, only Postback 1 will be received and it will only contain 2 digits - the source ID. If Tier 3 is achieved, you’ll receive 4 digits plus the source ID, and so on. See the graphic below for an overview of the details.
Postback 2 and Postback 3: The second and third postbacks allow you to measure in-app activity from day 3 through to day 7 and day 8 through to day 35. For apps with crucial events that occur within the first week and beyond, this is a hugely welcomed update. However, there are a couple of small catches. Fine grain conversion values are not available in Postback 2 and Postback 3, meaning the most granular data you’ll be able to receive here will be a coarse grain value. In short, coarse grain values can be mapped to either low, medium, or high (as opposed to fine grain conversion values which are mapped at 0-63).
Pro: The possibility to gain information, data, and insights up to day 35 and (potentially) for campaigns with lower volume.
Con: A coarse grain conversion value is the best you’ll get, Tier 0 crowd anonymity won’t receive them at all, and the postbacks will not be uniquely linked to the same device. You will, however, be able to link to the SourceID on an aggregated level, meaning you’ll have aggregated cohort data. We recommend mapping coarse grain values by assigning your users to the three value buckets (low, medium, high) to focus on specific events and/or revenue ranges expected further into the user journey.

This is our overview of how the measurement windows, postbacks, and crowd anonymity tiers work together:

Industry-wide adoption and getting your strategy ready

For SKAN 4’s features to be utilized, adoption needs to have taken place industry-wide and all stakeholders need to be set up technically. This means that app developers, ad networks, publishers, end users, and MMPs like Adjust all need to be fully up-and-running, and as this is a relatively resource-heavy task at many of the points in the ecosystem, this will take some time. There are also still a few unknowns, including how much volume a campaign will need to have to reach crowd anonymity or Apple’s privacy threshold and how dealing with SKAN 3 and SKAN 4 at the same time will work.

From the MMP side, Adjust is up-and-running and ready-to-go. Our open-source SKAN 4-ready SDK (SDK version 4.33.0) is now live and available and can be found on Adjust’s Github repository, here. This version supports SKAN 4 features including coarse conversion values and lockWindow. For more information on getting setup, how you need to prepare, and how you can build your strategy moving into 2023, reach out to your Adjust contact person or keep up-to-date with all of our latest iOS resources on the Adjust blog.