How long are most Podcasts? Are different types of Podcast longer or shorter? If a Podcast has long episodes, will it be more popular or less popular?
Our next three posts will try to answer these questions. Of course, the best answer to questions about Podcast length is to say that it shouldn't matter. The most important thing should be the quality of the content in the Podcast.
Still, I have found that many publishers want guidelines. They want to know which text articles may be too long or too short to turn into effective Podcasts. They also would like to know if there is a "sweet spot" for the length of a Podcast.
Let's start by looking at the average length of a Podcast. We are a little hindered in our research, because all of our data comes from the feeds we help produce. Sonibyte's customers are high-quality publishers who produce first-class, professionally-written content. Their Podcasts may have a different length distribution from individually-produced podcasts, podcast-based radio shows, personal journals, etc.
We will start by looking at the distribution of lengths for the Podcasts we produced between November 1 of 2007 and October 31 of 2008. (All of the statistics for the set of posts are based on the same time period. We weeded out some outliers and used a set of about 2,000 episodes for our analysis.)
The Podcast lengths in our data set range from as few as 91 words to as many as 9,000 words. The peak of the distribution is around 1,200 words and more than half of the episodes we produced were between 800 and 2400 words in length. A 1,200 word Podcast would take about nine minutes to read and would result in about a 5.3 MB file. (In case you wondered, a good rule of thumb is that a professional reader can pronounce about 2.2 words per second. One minute of professional-quality Podcast audio occupies about 0.7 megabytes of file space.) For most broadband Internet users, it should take less than a minute to download this file.
Podcast time-scales are in between contemporary music or a radio program segment (one to three minutes) and audio books or classical music (thirty minutes to several hours). We have suggested already that most Podcasts are consumed during activities such as driving or exercising. The range of times we see above fit the size of these time slots--and Podcasts are probably the only streaming/feed-type material, that suits them well.
Next, we will look at the distribution of time lengths within different types of Podcast.