Hi Excel Gurus;

I have another problem. I have 2 worksheets - data source and a
summary worksheet.

The source data worksheet has the following data :

A B
Customer 1 Product 1
Customer 2 Product 2
Customer 7 Product 2
Customer 5 Product 2
Customer 3 Product 2
Customer 2 Product 2
Customer 2 Product 3
Customer 3 Product 4
Customer 4 Product 4
Customer 4 Product 4

In the summary worksheet, I have the following summary worksheet:-

Type of Product No. of unique customers who bought
Product 1
Product 2
Product 3
Product 4

What formula can I use in the summary worksheet to derive the no. of
unique customer counts for each product. E.g for product 2, there are
5 records but there are only 4 unique customers? I tried sumif but dun
know how to get the formula to do unique count only. Appreciate your
advise. Thanks.