Distinct count of a dynamic range

[aaanenson]

I am looking for help with a distinct count of a dynamic range. In the attached example, I have written COUNTIF functions that take care of two metrics, but I am having trouble writing a function that will take care of the column titled "Number of Businesses." I have put in numbers in red to indicate what the number should be.

In my Excel spreadsheet I have Application Names repeated multiple times with data following it. For each application, I want to know the distinct count of Business Names associated with each.

There has to be a way to have Excel do this for me automatically. Can anyone help?