A First Touch model is a rules-based model that allocates 100% of revenue to the very first touchpoint of a conversion path within a given lookback window.. For instance, let’s say your conversion path consists of Email >> Video >> Display >> Paid Search >> Retargeting. In a First Touch Model, 100% of the revenue is credited to the Email event since it is the first touchpoint in the conversion path.
Note that events may happen beyond a particular lookback window — and these will not receive any credit. For example, if the marketer has a 30-day lookback window in the above example, and a Paid Social event actually happened 31 days before the conversion event — then that Paid Social event does not receive any of the credit because it occurred before the 30-day lookback window.