Multi Channel Conversion Attribution, also known as Cross Channel Attribution, lets you assign a value to each visit prior to a conversion. By default, when you view the channels that lead to a conversion, Matomo (Piwik) shows only the channel of the last non-direct visit. However, in reality, several channels usually contribute to a conversion as a visitor or user often visits a website several times before they actually convert. By applying different attribution models, you get a more accurate view on which channels actually lead to a conversion. This way you learn where to actually spend your money best when acquiring visitors.