SKAdNetwork (SKAN)

The dominant, mandatory privacy-preserving attribution framework for iOS app-install advertising, backed by Apple's platform authority

SKAdNetwork (SKAN) is Apple's native mobile measurement framework, first introduced in 2018 and significantly expanded in subsequent versions, designed to allow advertisers and ad networks to measure the effectiveness of app-install campaigns on iOS while preserving user privacy. It operates by having Apple cryptographically sign and deliver aggregated, anonymized conversion data to ad networks after a privacy timer expires, eliminating the need for device-level identifiers like IDFA. The framework became critically important following Apple's App Tracking Transparency (ATT) rollout in iOS 14.5 (2021), which dramatically reduced IDFA availability and forced the mobile advertising ecosystem to adapt to privacy-first measurement. SKAdNetwork functions as a system-level API built into iOS, meaning it is not a standalone company or commercial product but rather a technical standard and infrastructure layer provided by Apple. Ad networks register with Apple to participate, and when a user installs an app after seeing an ad, SKAN sends a postback to the ad network with limited, aggregated conversion data. Successive versions (SKAN 3, SKAN 4) have introduced improvements such as hierarchical conversion values, multiple postbacks, and crowd anonymity thresholds to balance measurement fidelity with privacy. In the AdTech ecosystem, SKAN has become a foundational measurement standard for iOS app advertising, influencing how MMPs (Mobile Measurement Partners), DSPs, SSPs, and advertisers architect their attribution and optimization workflows. Its limitations — including conversion value constraints, delayed postbacks, and lack of user-level data — have spurred significant industry innovation around probabilistic modeling, incrementality testing, and hybrid measurement approaches.