I run reports multiple times a day and until I get a system in place to filter out unsubscribes I have to do it manually. This is the formula I use find and remove matches.
- Select a blank cell next to the first column you want to compare (Name1), here I select B1, and type this formula =IF(ISERROR(MATCH(A1,$C$1:$C$10000,0)),"Unique","Duplicate"), and press Enter key, and drag the autofill handle down to fill this formula to the cells.
=IF(ISERROR(MATCH(A1,$C$1:$C$10000,0)),"Unique","Duplicate")