ExcelBanter - Can COUNTIFS be utilized to return unique values?

MICROSOFT QUERY 10/27/09:
I am using Excel 2007. In the example below I need to return a count of "2"
for each of the unique data elements in column "B" based on the values in
column "A". Repetitive column "A" data should only be counted once per
associated data in column "B". The data below is an excerpt from a
spreadsheet of over 9000 rows of similar data in which I need to return
counts on column "B".

Is this possible?

A B C
contact_id Completed By description
20LNWTGITX GARCIA, DEBORAH Indirect Confirmation
20LNWTGITX GARCIA, DEBORAH No Confirmation Made
B21T9A55B1 GARCIA, DEBORAH Direct Confirmation
WVYLBERITX HARRIS, CHARMAINE No Confirmation Made
WVYLBERITX HARRIS, CHARMAINE No Confirmation Made
BQFWA3AEM1 HARRIS, CHARMAINE Voicemail Confirmation
34V75WIITX SEIBLY, RONALD Direct Confirmation
20LNWTGITX SEIBLY, RONALD Indirect Confirmation
20LNWTGITX SEIBLY, RONALD No Confirmation Made