I was reading this article “Podcasting Ads Face Challenges” on Clickz.com, and thought you know the problems they outlined predominantly afflict the big players and the wide markets. But… if you’re into the Underachiever method, I think podcasts are a great way to read small niches. Whether you create the podcast yourself or seek to put ads in other people’s podcasts.
Subscribing to a podcast still takes several concious actions and the biggest concious action is actually listening to a podcast. It requires motivation. If a niche podcast has regular listeners I’d say they are motivated enthusiasts and motivated enthusiasts usually, not always but usually, spend money