If this is for free, may I suggest you release it via podomatic.
It`s a free system designed for podcasts, but what it does is track the amount of downloads, and where they come from, as well as have a good amount of trafic for promotion.

I was only told about this at the weekend, and I don`t really have time at the mo to check it out fully, but someone should take a look, it might be useful.