What is podcasting? Where did it come from? Do you need an iPod to do it? Is podcasting really the "next big thing"?
At the most basic level, podcasting is the delivery of audio files (typically MP3 audio), published in a way that makes it easy to subscribe to an RSS feed that checks for new files, automatically downloads them to your PC or Mac, and transfers the audio files to a portable media player (PMP). Using an RSS reader with support for audio and video enclosures, your PC automatically monitors the RSS subscription and at specified intervals downloads any new audio files added to the RSS feed. This is comparable to using a TiVo or Media Center PC to schedule recording of your favorite TV show every time it's ononly you never know when the next episode will air, how long the next episode will last, or even who will star in it.
Microsoft unwittingly pioneered this concept with their Plus! Sync & Go application for Pocket PC users, which was originally released shortly after the launch of Windows XP. Sync & Go doesn't use RSS, so it isn't officially podcasting, but it does exactly what podcast listeners want in an audio-delivery application. Sync & Go aggregates a list of available audio and video programming, to which you subscribe by adding programs to special Windows Media playlists. The programs automatically download to your PC on a "set it and forget it" schedule and sync to your Pocket PC each time you cradle it.
In the more immediate sense, podcasting is generally credited to two individual efforts. Dave Winer's UserLand first supported media enclosures in its Radio blogging product in 2002, making it possible to deliver audio files to the desktop via RSS. Adam Curry made this Radio feature useful just recently when he wrote a simple AppleScript to automate the process of getting RSS subscription audio files added to iTunes and automatically transferred to an iPod. Both Winer and Curry are also pioneer podcasters, offering their own on-demand audio programming available via RSS subscription.
In many ways, podcasting is barely different from what Chris Pirillo and I were doing with our talk-radio show back in 2000. We broadcast the show on a local Iowa radio station, burned the audio from the show to CD, did some minor edits using Sound Forge, and uploaded the show to Lockergnome.com for all takers to download. We even made an announcement in our newsletters the day the radio show went live online and were easily driving 3,000 downloads of each one-hour show. At one point, we offered an audio playercomplete with play, pause, and stop buttonsthat streamed the show on a weekly basis to desktops, automatically updating with the new show as soon as it went live. A company that is now part of Sausage Software deserves the credit for that innovation.
A big part of podcasting's appeal, at least to the people creating the podcasts, is the availability of the technology. To create a podcast, you record audio using easily accessible software, such as GarageBand for Mac users or the freeware audio editor Audacity, which runs on OS X, Windows, and Linux. Anyone can record an audio broadcast, upload it to the web, and enclose the file in RSS for distribution via subscription. This technique presents the potential for anyone with a topic, no matter how niche, to share ideas in an audio recording and make that recording available to the world, bypassing the need for traditional broadcasting channels such as television and radio.
Couldn't the Internet already allow anyone with a microphone connected to a PC to broadcast audio on the Internet? Hasn't Internet radio been around for ages, at this point? Technically, yes. The major difference between podcasting and what we think of as "Internet radio" is availability of content. In general, the availability of an Internet radio broadcast is now. You connect to the stream and hear whatever is currently playing on the stream. You don't get to rewind; you don't get to fast-forward. Just like AM and FM radio, you don't hear the beginning of an Internet radio stream unless you tuned in at the exact moment the stream started. With podcasting, however, you always get to start at the beginning and listen to as much of the content as you want.
What Will I Hear in a Podcast?
The topics of a podcast are entirely up to the podcast host. Like the early days of blogging, when many bloggers devoted countless hours of text to the future of blogging, many podcasts are filled with talking heads pontificating on the future of podcasting. Fortunately, several of the pioneers, including the previously mentioned Dave Winer and Adam Curry, along with Eric Rice, and Doug Kaye of ITConversations are finding talk-radio-style formats that maintain the casual feel of a blog in a structure that delivers enough ideas and entertainment to hold the attention of tech enthusiasts. My personal favorite podcast of the moment is the one hosted regularly by Engadget. If the ease of subscription catches the attention of traditional radio heavyweights like Howard Stern or Rush Limbaugh, all bets are off for how big this might become.
Is Podcasting Just for People Who Own an iPod?
Podcasting is absolutely not just for iPod owners. Virtually all podcast-distributed content is published in MP3 format. Almost all portable media players support MP3, including ones manufactured by Sony, Rio, iRiver, and Creative. Palm OS devices, Pocket PCs, and Smartphones also support MP3 playback. Taken as a group, this collection of devices is considerably larger than the population of iPod owners. Of course, podcasts are also playable on a desktop PC or Mac too.