I've always been of the opinion that podcast advertising is more targetted than main stream media (MSM). The number of listeners of a given show is typically smaller in the podcast world than the radio world, certainly, but they tend to be more interested. Podcasting isn't push media - listeners have to go out and get it.
Recently, I've started taking that thought to the next level and I've become convinced that podvertising should actually be worth more than msm advertising. It's nice to see some other people like Eric Schwartzman thinking the same thing:
If you’re an advertiser, why focus the majority of your marketing dollars on buying time in an outlet that reaches 600,000 with the objective of winning 6000 customers, if you can leverage search and media on-demand to reach that 6000 directly through a syndicated channel like podcasts? Why try to reach 2% of the audience, when you can reach 100% without interrupting 98% who couldn’t care less?
Bang on! If I can pitch my three-legged dog sweaters to 200 people with three-legged dogs then I want in. That's a much better proposition than pitching my sweaters to 100,000 dog owners who likely have no interest in my sweaters.