I have a table like this:
(sorry if the message mangles it, but there are tabs so you can paste
it correctly if you need to... I think)

Store Category Item
A 1 blahblah
A 1 blahblah
B 1 blahblah
B 1 blahblah
A 2 blahblah
A 2 blahblah
A 2 blahblah
A 2 blahblah
A 2 blahblah
B 2 blahblah
A 3 blahblah
B 3 blahblah
C 3 blahblah

I'd like to use a countif formula to generate the occurrences column.
Ideas?

Results
Location Category Number of Occurrences
A 1 2
2 5
3 1
B 1 2
2 1
3 1
C 1 0
2 0
3 1