I am trying to add the number of occurances of the word "yes" in one column,
and then adding the number of occurances of ID numbers in another. I will
try to give an example below:

A B C D
Doe John 12345 yes
Bob 12346
Ed 12347
Que Sue 23883 no
Mary 23884
Smith Joe 88464 yes

So basically what I want to do is wherever column D is yes, then I want it
to add up the number of ID numbers in column C and return a value (I am using
ID numbers as it is the best way to track). Thus based on the above, it
should return a value of 4.

I have been reviewing all the countif and sumproduct responses and trying
various things to no avail. Any suggestions?