I have a list of customers in column A and their sales in column B from 2013. I have the same data in columns C & D for 2012. Some of the customers in column A were not customers in 2012, and some of the customers in column C are not customers in 2013. I want one list that includes all customers, and produce sales for both years; if a customer bought in both years it would produce sales amounts in columns B & D; if just 2013 then only in column B and zero (or blank) in column D; if just 2012 then only in column D and zero (or blank) in column B.
I tried the LOOKUP function but it did not work; I do not know how to use the pivot tables.
Any suggestions?