What is Crowd anonymity? 

Crowd anonymity, or Apple’s new way of ensuring users DON’T stand out from the crowd, refers to the protection of individual user data by aggregating it within a larger group of users, making it impossible to distinguish or identify single users within the data set. This approach ensures that while advertisers receive useful information about user behavior, the privacy of each user is preserved.

Within the SKAdNetwork framework, crowd anonymity is crucial in balancing the scale between user privacy and marketing attribution. It ensures that while advertisers can track the performance of their ad campaigns in terms of conversions and app installs, they do not receive granular data that could compromise user privacy.

What data can advertisers get in each tier?

Overall

The SKAN 4.0 framework establishes tiers of crowd anonymity. Each tier reflects a different level of user aggregation required before data is shared with advertisers. Lower tiers represent smaller groups and thus provide less specific data, while higher tiers, which aggregate data from larger groups, allow for more detailed reporting without compromising anonymity.

The crowd anonymity tier will have a say in the following conversion postback elements: 

• Does the postback get sent or not 
• What type of conversion value (if any) gets included: fine-grained, coarse-grained, or none
• How many digits of the source identifier are disclosed: all digits, 3 digits, or only last 2 digits
• The source app ID is included or not

Detailed data provision

Tier 0: At this lower end of crowd anonymity, the install count is low and therefore doesn’t meet the privacy threshold. As a result, you’ll get:

• 2-digit source identifier 
• No conversion values in the first postback
• No further postbacks

Tier 1: Also sits at the lower end of crowd anonymity, but with enough installs to meet the privacy threshold. In this tier, you’ll get:

• 2-digit source identifier 
• The coarse-grained conversion value

Tier 2, at a higher crowd anonymity level, you’ll get:

• 2-, 3- or 4-digit source identifier in the first postback
• 2-digit source identifier in postbacks 2 and 3
• The fine-grained conversion value in the first postback
• The coarse-grained conversion value in postbacks 2 and 3

Tier 3, at the highest crowd anonymity level, you’ll get:

• 2-, 3- or 4-digit source identifier within the first postback
• 2-digit source identifier in postbacks 2 and 3
• The fine-grained conversion value in the first postback
• The coarse-grained conversion value in postbacks 2 and 3
• The source-app-id (for in-app ads) or source-domain (for web-to-app ads)

Or you can refer to these pictures for a better summary 

SKAN, Crowd anonymity and Airbridge

If all of those things seem hard to understand and work with, do not worry - Airbridge supports both SKAN 3.0 and SKAN 4.0. For SKAN 4.0 specifically, Airbridge can help you receive and decode the conversion data from all three SKAN 4 measurement windows, together with pinpointing the best campaigns for each postback data tier.

Airbridge SDK can get your app updated, or you can establish a SKAN 4 setup via Airbridge to leverage features such as the Lock window, coarse conversion values and the source ID for more precise targeting and better web-to-app campaign development.

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