Transactions over a month broken down to each product type?

I have a set of sales data which shows the dates of transactions and also the product type that was sold. I want to see the monthly sales for each product type. I can get a total for all product types over the months using the following:

=COUNTIF(Licences!E2:E9999, "<39600")-COUNTIF(Licences!E2:E9999,"<39569")

36900 = Jun-08
39569 = May-08

But I need it to also break it down for product a, b, c so I need something else to add to the formula?

Thanks in advance