By date the "appeared", you mean the date the first became a customer,
right? For new customers in March, you want the entries that are greater
than or equal to March 1st. If so, try:

=sumproduct(--(a1:a1000=date(2009,3,1)))

If you want to isolate a particular date range, use:
=sumproduct(--(a1:a1000=date(2009,2,1)),--(a1:a1000<date(2009,3,1)))

Adjust the range to suit.

Regards,
Fred.

"Rookie_User" wrote in message
...
My goal is to demonstrate how many NEW customers are added each month. So
if
a customer existed in January and also existed in February, they would
only
be counted in the January total. If a customer appeared in March and not
the
previous months then it would be counted only in March and not future
months.
I am basically trying to determine the acceptance of a particular service.

I have two columns; one that has customer id and the other the month they
appeared. I know a long way to get what I want but am looking for a more
efficient method.