Chris Lynn and I recently wrote an article for Practicing Anthropology discussing the how and why we podcast for the Human Biology Association. The short and sweet answer is that it is a labor of love. We love what we do and all the amazing people we get to interact with, and we want to share that through the Sausage of Science.
This article also provides a brief road map of how to go about making your own podcast if you are interested. Here is the link the article abstract, feel free to contact me for a pdf. Also, here is a link to the blog post Chris wrote about the article!