Attribution

Definition

Attribution is the process of assigning credit for a conversion to one or more marketing touchpoints in the user journey. When a customer discovers a product through an ad, returns via an email, then purchases through organic search, attribution determines each channel’s contribution.

Attribution models in GA4

GA4 uses the data-driven model by default, which leverages machine learning to distribute credit among touchpoints based on their actual contribution to the conversion. This is a major shift from Universal Analytics, which used last non-direct click by default.

Other available models include: last click (cross-channel or ads only), first click and linear. Google retired the position-based and time-decay models in 2023.

Attribution windows

The attribution window defines how far back a touchpoint can receive credit. In GA4, it is configurable: 30, 60 or 90 days for acquisition clicks, and 7 days by default for engaged views. These settings are adjusted in Admin > Attribution.

Limitations and reality

No attribution model is perfect. Multi-device journeys, GDPR consent blocking cookies, and private browsing create gaps in the measured journey. Reliable attribution analysis requires robust tracking and a clear understanding of each model’s inherent biases.