At a minimum cost of $40 per thousand downloads, podcast advertising gives companies a relatively inexpensive way to reach ultratargeted markets, according to Fruitcast.com, a service that helps businesses advertise on podcasts. Because podcasts usually appeal to narrow, topic- or geography-specific markets, podcasting helps advertisers reach hard-to-define audiences. Fruitcast.com offers free consultations to businesses considering this medium, and it will also help advertisers create and upload their spots. Still not sure? Go to the site to browse a directory of podcasts that are accepting advertising.