First-click attribution

First-click attribution is a general model assigning all conversion credit to the first eligible click in the measured journey. Google describes this rule in its historical Universal Analytics documentation.[2] This explains the model rather than claiming it can currently be selected for GA4 reporting; Google states that first click is no longer available there.[1]

The model can help a merchant examine which interactions begin a measurable journey. A later newsletter or search ad receives no closing credit under this rule. The first measured click is not necessarily the shopper's first encounter with the brand either. State the observation window and visible channels before using this model to judge a discovery campaign.