In our conversations with clients and prospects, we’ve heard about the industry-wide need for clearer information about SKAdNetwork. 

As the privacy-focused contextual mobile DSP, Dataseat is proud to be the industry’s longest-standing expert in SKAN. We navigate within the constraints of crowd anonymity and privacy thresholds to empower our advertisers with solutions that make SKAN-only campaigns optimizable and more efficient. One of our ongoing goals is to improve measurability of mobile user acquisition (UA) campaigns using iOS SKAdNetwork. 

That’s why we built a quick reference doc for SKAN 4.0 Postback Parameters that you can use internally. 

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SKAdNetwork (SKAN) 4.0 postback parameters subject to privacy thresholds

With SKAN Apple introduced privacy thresholds to ensure postbacks sent to the advertiser / ad-network could not be tied back to an individual user. Apple will withhold important postback information (parameters) if privacy thresholds (i.e., install volume by campaign within a 24-hour period) are not met. You will find the list of the postback parameters subject to privacy thresholds below.

  • Source Identifier (formerly campaign ID): The unique identifier assigned to a SKAN campaign. This is returned back in the form of a two-, three-, or four-digit number, depending on the level of privacy threshold met. Source Identifier is assigned by the ad network/DSP. Also referred to as Source ID.
  • Source App ID (applicable to app traffic only): The Apple app ID where the install came from (i.e., where the winning ad appeared).
  • Source Domain (applicable to web traffic only): The website domain where the install came from (Safari browser only).
  • Conversion Value (coarse-grained): General insights into the in-app actions a user takes post-install. This is returned back as high, medium, or low, in advertiser-defined groupings. Coarse-grained conversion values are subject to lower privacy thresholds than fine-grained and can be received during the first, second, and third postback windows
  • Conversion Value (fine-grained): Detailed insights into the in-app actions a user takes post-install. This is returned back in the form of a number (0-64) assigned by the advertiser. Fine-grained conversion values are subject to a higher privacy threshold than coarse-grained and can only be received during the first postback window

Summary of postback windows:

Summary of postback windows

Conversion Value example:                                      Source Identifier example:

Conversion value, source identifier

Image source: Apple

Summary of crowd anonymity tiers

With SKAN 4.0, Apple brought forth the concept of crowd anonymity to allow for more actionable campaign data to be returned to the advertiser / ad-network while maintaining user privacy. There are now four tiers of crowd anonymity (while previous versions of SKAN only had one tier) which are determined by Apple and based on install volume by campaign (crowd size). The crowd anonymity tiers and associated postback parameters returned are as follows:

Tier 3

Tier 2

Tier 1

Tier 0

Highest Crowd Anonymity data received High Crowd Anonymity data received Medium Crowd Anonymity data received Low Crowd Anonymity data received
  • Fined-grained conversion value
  • 4-digit Source Identifier
  • Source App ID
  • Fine-grained conversion value                                
  • 4-digit Source Identifier


  • Coarse-grained conversion value
  • 2-digit Source Identifier
  • 2-digit Source Identifier

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To download a PDF version of this resource, click here: Privacy Threshold Overview (SKAN 4.0) PDF 

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Get started with SKAN 4.0

Could you use another set of eyes on your SKAN configuration? Let’s sit down and discuss how we can make it work with your user acquisition on iOS. Feel free to get in touch with Dataseat’s team.