Where TotalRevenue is the revenue a customer has generated across products, AllAdvertising is the sum of advertising methods recorded for the customer, and the specific advertising method is the advertising channel of interest. In this way the revenue a customer generates is evenly attributed to each marketing method that they engaged with. If a given advertising channel did not result in a purchase for that customer, then no revenue is attributed to that channel. This large assumption that the revenue is evenly distributed across advertisements severely limits the accuracy of the advertising-revenue relationship but is necessary given that the data was already aggregated into sum figures rather than individual transactions. This accuracy could be improved given the unaggregated data, which would require a more data driven business practice.