VoloMedia

VoloMedia provides online advertising and audience measurement solutions for portable and downloadable media, like video and audio podcasts as well as full iTunes support. Their primary service provides for the management of content, ad campaigns, advertising insertion, dynamic online ad rotation, audience metrics, and download reporting.

VoloMedia's technology is also integrated with other technologies and product, for example (from the website):

Our plug-in architecture contains interfaces for many types of integrations. As examples in the market, we have integrations with the leading CDN providers in Akamai, Limelight, and Pando. Other integrations such as DoubleClick DART and Adobe Media Player are on the product road map.

This seems like it could be worth a try if you have podcast content that has yet to be monetized.

UPDATE

Their website doesn't appear to be online at the time of this updated review, but you can check by cutting/pasting this into your browser to see if it's back online or not: volomedia.com