Types of Attribution Models
Last-click attribution gives 100% credit to the final interaction before conversion (Google Ads' historical default). First-click gives all credit to the first touchpoint. Linear distributes credit equally across all touchpoints. Time-decay gives more credit to interactions closer to the conversion. Position-based (U-shaped) gives 40% to the first and last touch with 20% split among middle touches. Data-driven attribution uses machine learning to assign credit based on actual contribution patterns. Google Ads now defaults to data-driven attribution for most conversion actions.