In television and radio, it costs the same to reach 10 people as 10,000 or 10,000,000. In fact, the sunk costs of transmitters and FCC licenses inherently bias toward larger audiences. If everyone within range of your transmitter isn’t paying attention to you, there’s still marketing to be done.

On the other hand, the distribution technologies in podcasting inherently bias smaller audiences. Each additional website visitor adds to the load on web server, an additional straw on the proverbial camel’s back. Eventually, the server can’t take it and crashes (slashdotting). Adding insult to injury, when a podcast suddenly gets popular the site is slashdotted, the publisher’s monthly bandwidth allocation is also gone.

With the release of iTunes 4.9, some of the most popular podcasts were taken down, right as their demand peaked. In the same way the goal of viral marketing is to turn customers into the marketing department, Dave Slusher and Leo Laporte are experimenting with BitTorrent to transform their listeners into their distributors. BitTorrent turns internet distribution into something more akin to broadcasting, where each additional visitor makes it easier on the publisher. Unfortunately, iTunes doesn’t yet support BitTorrent. iTunes does support video-casts, and given video files are a magnitude of size greater than audio files, this is worrisome.

Aside from the tag-driven directory at Odeo.com, all of the podcast directories start with a limited number of high-level categories (19 in the case of iTunes). Any finite number of generic top-level categories inherently conflicts with podcasting’s bias toward extremely niche conversations. In the same way Yahoo’s top-level categorization conflicts with the web’s inherent bias toward extremely niche conversations. For more on this, listen to Clay Shirky’s Ontology is Overrated presentation at ITConversations.

Notice the above link is to a specific presentation at ITConversations – categorization at the individual podcast-level is more useful than categorization at the podcaster-level. I’ll extend this further; if two podcasters fall under a same category, both of them need to specialize further.

Soon the best, most relevant, most engaging podcasts won’t be listed in iTunes or any directory. The risk of slashdotting and mis-categorization is too high.

As Groucho Marx famously stated:

“I don’t want to belong to any club that will accept me as a member.”