Last click is a term used in the context of online advertising to refer to the attribution model that attributes the conversion or sale to the last ad or channel that the user interacted with before converting. The last click model is commonly used in digital marketing, as it is simple and easy to understand, and can provide a clear picture of the performance of an ad or channel. However, the last click model has been criticized for being overly simplistic and for not adequately accounting for the contributions of other ads or channels in the conversion process. As a result, other attribution models, such as first click or linear attribution, have been developed to provide a more comprehensive and accurate view of the role of different ads and channels in the conversion process.