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.”

The new iTunes 4.9 supporting podcasts is out today, it will do wonders for increasing the visibility of the most popular podcasts and radio station-produced podcasts. This is definitely the easiest way to subscribe to a podcast, whether browsing or manually. Until iTMS URL linking is functional, it’s a two step process to subscribe to a podcast. Still the easiest and simplest process.

Update: Podcaters, swap out the ‘http’ with ‘pcast’ in your feed URL and you’ve got iTunes 1-click subscription. Special thanks to Jason Ruby at the Delta Park Project for doing the legwork on this.

As expected, browsing the iTunes podcast directory is similar to browsing the iTunes audio book directory – after selecting a genre, the best way to navigate is using the ‘search’. This is works great for known things (my iTunes Library) – it’s far less useful for unknown things (all the podcasts in the world).

I’m migrating my audio-only podcasts to iTunes, the podcasts + weblog I enjoy are remaining in NetNewsWire. Here’s what I’ve seen thus far; The Gillmor Gang is available, but not the Gillmor Daily. This Week in Tech is available, though iTunes doesn’t know what to do with the torrent file. The First Crack podcast is in, though not the latest show (it shows up after subscribing) and the artwork is missing. Finally, unlike all the ipodders to date, iTunes doesn’t offer a way to export your podcast subscriptions in a way you can share them.