One of the clients who uses our podcasting voiceover services recently asked me, "how long does a Podcast last?" Since I prefer to be lazy, if I can, I turned to Google, for an answer. Surprisingly, I did not see much information on this subject.
There is a good (if a bit dry and academic) study on Web news article on this subject from authors Dezso and Almaas. It shows that (at least for a Hungarian site) 28% of visits to a Web news article occur on the first day, 7% on the second, and that visits decline following a power law formula to a low, but surprisingly steady value. Is the same true for podcasts?
Our Sonibyte clients don't do music podcasting or radio program podcasting. Instead, they are doing news, newsletter, and informational casts. That means that their content is similar to that of the news items that the Hungarians studied. We have several years of good information on how many downloads each of our client podcasts receives. The chart below shows the first 180 days of download activity for about 90 podcasts that were published in the third quarter of 2007. As you can see:
1. About ten percent of all downloads occurred on the first day of publication. Another 13% occurred on the second day.
2. The number of downloads declines pretty smoothly, except for a "blip" at day seven. This is probably because most of our customers are all on a weekly publication cycle. The release of a new podcast in a series seems to stimulate demand for the most immediately preceding podcast (almost doubling downlaods, versus the trendline).
3. About 50% of the first six months worth of downloads occur in the first 15 days. After that, there is a slow and fairly smooth decline through the end of the period we measured.
What does this say about podcast longevity?
1. The first two weeks are pretty important. In fact, if your podcast doesn't get a lot of traffic in the first three days, it is probably never going to be widely downloaded.
2. More total downloads will happen after the first two weeks than during them. This means that you should probably continue to monitor, update, market and promote your podcasts, long after they have been originally published.
We will next look at the variation between different podcasts and see how downloads are distributed, among them.



