One of the best [language podcasts] is JapanesePod101.com, a daily podcast. The sponsor is a Tokyo-based translation service, which makes perfect sense. Loyal subscribers -- a very targeted audience -- receive daily brand reinforcement.
She points out that the JapanesePod101 has hit the holy grail of podcasting: a targetted audience, a loyal audience with a reason to keep subscribed, and a daily dose of branding.
This is a great example of how to leverage the particular distinctiveness of podcasting (full points to anyone who got the Borg reference) to enforce your brand.