I am working with a graph of Order Date (x axis) and cumulative order value (y axis). This is for a monthly recurring subscription service. I need to subtract a cost (the CPA) from the first instance of the customer ID appearing in the data.
My current method subtracts the CPA from every instance of the customer ID, rather than just the first instance. There should only be 1 CPA per customer, so sum(CPA) = [CPA]* Distinct ( Count ( customer_id ) )