Martin Just wrote...
>Hi all. Got a long list of shipment records. Orders can have multiple
line
>items of varying quantities and can ship on multiple days.
>
>I want to count how many unique orders were shipped on any given day
for
>each customer.
>
>Order Line Customer Shipdate
>A 1 Ted 1/12/05
>B 1 Mike 1/12/05
>A 2 Ted 1/12/05
>C 1 Mike 1/12/05
>
>Total unique orders shipped to Ted on 1/12/05 = 1
>Total unique orders shipped to Mike on 1/12/05 = 2

The general approach to counting uniques is

=SUMPRODUCT(1/COUNTIF(Range,Range))

With criteria, you need to use something like (assuming data in A2:D5)

=SUMPRODUCT((C2:C5="Ted")*(D2:D5=--"1/12/2005")
/(COUNTIF(A2:A5,IF((C2:C5="Ted")*(D2:D5=--"1/12/2005"),A2:A5))
+1-(C2:C5="Ted")*(D2:D5=--"1/12/2005")))