Composed of rules, or sets of rules, that determine how credit for sales and conversions are assigned to touchpoints in conversion paths. For example, the Last Interaction Model assigns 100% credit to the final touchpoints (i.e., clicks) that immediately precede sales or conversions. Other models include: Heuristic models, Shapley models, Data-driven probabilistic models, and Agent models. Bidding and budget allocation can be done with Multi-Touch Attribution models (MTA).