What is SKAN 4 crowd anonymity?

SKAdNetwork 4 (SKAN 4) expands upon the privacy threshold from SKAN 3 and earlier by introducing crowd anonymity. Broken into four tiers of anonymity (0, 1, 2, and 3), postbacks received via SKAN 4 contain different amounts and types of data depending on which crowd anonymity tier was reached. The idea is that user privacy is better preserved when there is a higher volume of installs, because after a certain threshold is met, it should become impossible to match the data points to individual users or devices.

Up until SKAN 3, marketers and advertisers working with SKAN were able to receive a single postback containing a conversion value, but only if the campaign met Apple’s specific privacy threshold. If this threshold wasn’t met, the postback would contain a null value (CV=0) in place of a conversion value. This became known as the “dreaded null”.

SKAN 4 changed this system by introducing its four-tiered crowd anonymity, which, along with coarse conversion values and an increased number of postbacks and measurement capacity, opens up the opportunity for more granular measurement than before, and, ideally, less nulls.

The data received in a SKAN 4 postback is determined by the crowd size associated with the app or domain displaying the ad, the advertised app itself, and the hierarchical source identifier provided by the network. Every time an install occurs, Apple assigns a tier and uses this to determine the data that will be received in the postback.

Depending on which crowd anonymity tier your install or campaign is assigned, you’ll receive different types and amounts of data in your postback. Note that for measurement windows 2 & 3, along with their corresponding postbacks, even a tier 3 crowd anonymity will only have the chance to receive a coarse conversion value. Fine values are only available in the first measurement window and the first postback.

What you get per crowd anonymity tier:

• Tier 0: Install volume too low to meet Apple’s baseline privacy threshold. The only data received in this postback will be two source ID digits.
• Tier 1: Install volume high enough to meet the privacy threshold, but not to receive a fine value. You’ll likely receive two source ID digits and a coarse value.
• Tier 2: Volume is high enough to potentially receive a fine value in the first postback, a coarse value in the second and this postbacks, and two-four source ID digits.
• Tier 3:  The privacy threshold is met and you should receive a fine value if it’s the first postback (coarse in postbacks 2 & 3), two-four source ID digits, the source domain (identifier of the domain that displayed the web ad) or the source app ID (identifier of the app that displayed the ad).

The table below demonstrates how the crowd anonymity tiers work together with the measurement windows and postbacks:

Adjust’s iOS & SKAN Solutions make succeeding on SKAdNetwork easy for app marketers. You can leverage our suite of solutions to map conversion values for SKAN 3 and all three SKAN 4 measurement windows, and leverage SKAN Analytics to understand which campaigns are delivering the best results and which networks are resulting in higher rates of tier 2 and tier 2 crowd anonymity.

With a fully optimize SKAN 4 strategy, the crowd anonymity tiers should help in the process to:

• Reduce null conversions received in SKAN postbacks.
• Provide data for more granular reporting than was possible with SKAN 3 and earlier.
• Open up new measurement opportunities via coarse conversion values later in the user journey.
• Associate fine conversion values with distinct events and activities, now that they can increase and decrease.

As adoption continues to rollout, there’s never been a better time to start working with SKAN 4 and getting ahead of next-gen measurement. Simply ensure you update the Adjust SDK in your app, set up a SKAN 4 configuration with Adjust so you can take advantage of features like lockWindow and coarse conversion values, utilize the source ID by working with your ad networks to determine the best possibilities for granular targeting, and even start testing Safari-to-app campaigns.

To find out how we can support your iOS success, see our iOS & SKAN Solutions, reach out to your contact person, or request a demo today.