I believe I saw the granules used on a date farm a few years ago. The granules are the residue from pressing to extract the oil. As I recall, they were used both to kill some soil borne pests, and as a fertilizer. They were applied quite heavily around the trees: like a mulch. I would guess that they were using 1-2 pounds/tree. That's somewhat consistent with what I see as recommended dosages on the web. One of the things I most recall about the area where they were used was the rather strong but not unpleasant smell produced.
Renais

Thank you for the reply. I've done some more searching online and see that it is also referred to as neem cake. What's odd is that I'm having difficulty locating U.S. sources...not sure why that is...

Neem doesn't kill insects it disrupts their life cycle and makes normal food undigestable or maybe just unpalatable . I use it in my potted plants and it defiantly helps. I mix it with EWC abd use it as a top dressing or mix it in the first few inches of soil ...
Sometimes you can find it at the Hydro stores ,Yes I know seems silly but the organic pot growers love it
Neemresource is a good online supplier.