Hello,

I suggest NOT to use the SUMPRODUCT divided by COUNTIF approach
(please see entry 3 of my Excel Dont's:
http://www.sulprobil.com/html/excel_don_ts.html
) and NOT to use the Morefunc addin (entry 1 of that same list) but to
take Charles Williams' COUNTU function.

Please find my analysis on this he
http://www.sulprobil.com/html/count_unique.html

Regards,
Bernd