We broke down the 40,000 Podcasts we think are currently available into a
set of 15 categories. We then stepped
out on a limb and estimated the size of the Podcast market last year at 500
million downloads (see our last post). OK,
so which categories of Podcast are most popular and get the most downloads, and
which lag behind?
Feedburner, iTunes, and Podcast Alley list which of the
Podcasts in their directory had the most downloads. We categorized the Podcasts they listed and
calculated what percent of them were in each category. If we assume that the popularity of all
Podcasts falls in the same general pattern as it does for these top entries, we
get an estimate of overall popularity by category.
The table below gives the estimate we get from the above analysis for
popularity by category, along with the distribution we gave earlier for the
categories in which Podcasts are published. The contrast between popularity by download and popularity by number of
Podcasts produced is interesting:
iTunes
Podcast Subject Categories
Estimated % of
Downloads
Estimated % of
Podcasts Published
Download/Publish
Percentage Ratio
Arts
6.70%
9.90%
0.7
Business
4.10%
6.00%
0.7
Comedy
16.20%
7.40%
2.2
Education
5.50%
4.30%
1.3
Games &
Hobbies
4.50%
4.10%
1.1
Health
4.60%
3.60%
1.3
Kids &
Family
0.80%
2.00%
0.4
Music
6.40%
16.50%
0.4
News &
Politics
9.30%
8.40%
1.1
Religion &
Spirituality
6.80%
7.60%
0.9
Science &
Medicine
3.30%
3.10%
1.1
Society &
Culture
12.10%
11.20%
1.1
Sports &
Recreation
2.90%
6.30%
0.4
Technology
8.10%
6.10%
1.3
TV & Film
8.80%
3.40%
2.6
Total
100%
100%
If you are considering launching a new Podcast, you could focus on an area
that has a lot of downloads and relatively fewer competing feeds. With this strategy, our list above suggests
the best areas are TV & Film and Comedy. Instead, you could choose to go where the traffic is and to heck with
the competition (aren’t you brave!). Then, you’d pick Comedy (again), Society & Culture, or News &
Politics. Note that it looks hard to get
much traction from launching a new Podcast in Music, Sports & Recreation,
or Kids & Family.
These past four posts have presented an overview of the category structure
of the Podcast market, its size and growth rate, and the relative popularity of
different types of Podcasts. We have
tried to be conservative and to share the evidence that supports our
estimates. Please argue with and/or
discuss these numbers. Our industry
needs more information and an open discussion about its size and composition,
if we are going to attract the respect and attention these numbers suggest we
deserve.
So far, we’ve provided evidence that there are about 40,000 “stable” English
language podcasts (plus some number of “ephemeral” ones) that were downloaded
in 2007 by about 20 million American podcast listeners. How many times did this audience download
Podcasts each year and which types did they download most often?
Let’s assume the following things are true:
1.The
Podcast market is a Long
Tail market that follows a power rule
distribution.
2.There
are about 40,000 total podcasts in the market.
3.Feedburner’s subscriber statistics cover one
third of the top one hundred podcasts.
4.For
each subscriber to a Podcast, there are another four people who download its
episodes. (See previous posts by us, on
this issue.)
5.The
average Podcast has one episode per month. (This makes monthly subscription info fit well with annual estimates.)
If these things are true, we can use the number of subscribers
for top 100 audio podcasts on Feedburner, to calculate the number of
downloads made in 2007. We can fit their
data to a power law curve, and estimate the coefficients of the curve. We can then integrate across an assumed
universe of 40,000 feeds to get the total downloads for all of these feeds. (If you want to see the charts and math
behind this, send me an email!)
Our estimate from this process is that there were about 500 million podcast
downloads last year. If 20 million
people listened to these Podcasts (per the surveys I mentioned in the last
post), they would have downloaded an average of about 25 Podcast episodes during
the year.
Of course, downloads were probably skewed and concentrated. The Universal
McCann survey I mentioned earlier estimated that about 25% of the Podcast
audience made a daily download and 35% downloaded at least once per week. If they are correct, the core 60% of our
audience (12 million users) consumes about 97% of all Podcast downloads.
Most Podcasts do not currently carry advertising. However, those that do are earning between $5
per thousand downloads and $50 per thousand. (These numbers are based on our own experience with ad placement and on
discussions with other companies in the Podcast industry.) If we pick a median value of $20 per thousand
downloads, the English language Podcast ad market was worth about $10 million last
year.
We have seen a download growth rate over the past two years within our feeds
of more than 75% per year.
At that pace, the Podcast advertising market has
the potential to reach a value of $17 million in 2008 and $100 million in about
four years (by 2011). While that is still
a small market, relative to behemoths such as radio advertising or Web
advertising, it is big enough to be interesting!
The last post described a reasonable way to categorize Podcast subject
matter, based on fifteen iTunes categories. There are more than 100 active Podcast directories, and it would be
impossible to search, inspect, and categories the thousands of Podcasts they
list. Instead, we looked at seven
directories that had summaries of their listings by category. We then mapped their categories to the iTunes
category system, to get eight independent estimates of the distribution of
Podcasts by subject. Based on this data,
we made an estimate of the distribution of Podcasts by subject.
This was a list only of what feeds have been created—not which subjects are
listened to, most often. The categories
with the most feeds seemed to be "social" ones—music commentary, news
& political commentary, rants about life or love, personal journals, and
other soft stuff that comes from the heart. Second place went to what I
would describe as "education." This included language lessons,
help with personal finance, information on games and hobbies, and podcasts
about science, medicine or health. The last group of categories--but not
far behind--was entertainment. TV & film, and comedy are in this
group.
As I mentioned earlier, iTunes has about 2,000 entries for each of its
categories. If their catalog is
comprehensive (i.e., included every published podcast feed), the Podcast market
would have about 35,000 feeds. However, when
one compares the listings on the different directories, each has some unique
items. It is likely that some Podcast
publishers don’t get around to listing on iTunes. So, let’s be conservative and add another
5,000 “active” podcasts to those listed already on iTunes, for a total of
40,000 active Podcast feeds. (English
language-only!) Of course, there could
be 10,000 or more additional Podcasts that have only a single episode, are no
longer being produced, etc. Some of
these “ephemeral” entries could develop into stable feeds. But most are likely to remain undiscovered,
unappreciated, and unexploited.
A recent survey
by Edison and Arbitron showed that 18% of the households they surveyed had
listened to an audio podcast in the past year. That suggests that at
least 20 million US consumers listened to Podcasts last year. A similar
study by eMarketer apparently estimated 18 million Americans listened to
Podcasts in 2007. (I say apparently
because the details of the study are available only to those who buy their
study.) A recent
Universal McCann study says about 30 million Americans have downloaded a
Podcast. This study lumps audio and
video Podcasts together. Therefore, I think it supports the figures for audio Podcasts only, from the other studies.
Let’s assume we had about 20 million Americans downloading Podcasts in
2007. How often did they download
Podcasts? Which categories did they
download the most? We’ll put our guess
on the answers to these questions in a future post.
The podcast market suffers from a sorry lack of reliable and
objectively-derived statistics. There are many reasons for this.
One is that a podcast can be hosted and served from almost anywhere in the
Web--there is no central repository or clearinghouse for them. A second
is that the amount of money spent on podcast ads is still small. Until it
gets bigger, the market will not attract the kind of tracking and validation
services that provide audience figures for TV, radio, or large traffic Web sites.
Finally, the biggest distributor of podcasts is Apple,
via its iTunes store. And, as most
of us know, Apple is pretty secretive about its products and their performance. As far as I know, Apple does not share any
download or subscriber statistics on the thousands of Podcasts it lists on
iTunes.
The lack of statistics means that we must be creative if we want to answer questions
such as “How many podcasts are available?,” “How many podcasts are downloaded
each year?,” or "What podcast subjects are popular?" We can not
get any absolute answers to these questions, but we can put together some
reasonable estimates by looking at various podcast directories and feed listing
services.
Before starting this process, we need a way to categorize the subject matter
of podcasts. I decided to use iTunes’
categories for my study, because they seem to represent a sensible and fairly
complete schema. Also, most podcasters
upload their feeds to iTunes, and therefore have been influenced by the iTunes
category structure:
iTunes
Podcast Subject Categories
Number of
Podcasts Listed on iTunes
Arts
2,364
Business
2,277
Comedy
2,115
Education
2,180
Games &
Hobbies
2,161
Government
& Organizations
2,167
Health
2,362
Kids &
Family
2,219
Music
2,172
News &
Politics
2,162
Religion
& Spirituality
2,223
Science &
Medicine
2,338
Society &
Culture
2,175
Sports &
Recreation
2,325
Technology
2,209
TV & Film
2,176
Total
35,625
(BTW, this series of posts is based on data gathered between May and July of
2008. It is of course quite possible, that
iTunes will change their category structure without notifying me!)
I've given above the number of podcasts that iTunes carries for each
subject. Do you find it as strange as I do, that each category seems to
have almost the same number of entries? Does this mean that Apple
"trims" old podcasts out of its directory after a while, to keep the
list for each subject from growing too big? Or, has Apple constantly
juggled and redefined its categories, so that they stay the same size?
I'm relatively new to this industry and would love to have help on this
question, from someone who has observed iTunes longer than I have.
If you are interested, you can find similar category lists on Podfeed.net, Blast, Odeo,
Podcast Pickle, Zune, Podcast
Nation, and Digital Podcast. (Note that I am only studying English
language Podcasts in these posts. There
are many directories in other languages, that I have not addressed.) Each of these directories has its own
variations and oddities—partly because each is oriented towards its own sub
market within the podcast space. Still, we can consider each of these lists
to be an independent estimate of the distribution of Podcasts by category. By combining category data from these seven
directories with the information from iTunes, we were able to build this
estimate of the overall distribution of Podcast publishing by category:
iTunes
Podcast Subject Categories
Estimated % of
Podcasts Published
Arts
9.9%
Business
6.0%
Comedy
7.4%
Education
4.3%
Games &
Hobbies
4.1%
Health
3.6%
Kids &
Family
2.0%
Music
16.5%
News &
Politics
8.4%
Religion &
Spirituality
7.6%
Science &
Medicine
3.1%
Society &
Culture
11.2%
Sports &
Recreation
6.3%
Technology
6.1%
TV & Film
3.4%
Total
100%
It makes sense to me that the biggest number of published Podcasts is in the
Music category. Music is where
Podcasting got its start, and many Podcast listeners are well-educated on
musical and other audio subjects. (Our
company, Sonibyte, was started by
musicians!) Society & Culture made
sense as number two, since this category contains all types of personal
commentaries, rants, and Web-cast radio shows.
As I struggled to map the data from the smaller directories to the iTunes
categories, I found three categories that were especially troublesome:
ðArts: Apple includes literature, performing arts,
and visual arts in this category. The
latter group overlaps with the TV & Film and Entertainment categories that
other directories use. Apple also
includes fashion it its Arts category. Other directories put these Podcasts into their Society & Culture
types of category. There is a large
group of Podcasts that relate to story telling or serial novel creation. These should probably be in the Arts
category, but some directories also put these into a Society & Culture
category or into a separate literature or storytelling category.
ðGovernment
& Organizations: No one else
besides Apple seems to have this category. I didn’t see any entries from this list on Apple’s list of top
podcasts. Since I can’t match it up
anywhere and the traffic from this area is probably not that high, I dropped
this category from our study.
ðHealth
and Science & Medicine: iTunes
splits health-related stuff into self-help, fitness, and sexuality topics (Health)
and scientific/factual stuff (Science & Medicine). Spiritual approaches to health go into the
Religion & Spirituality category. This is complex enough that I suspect a lot of entries in these groups
overlap or are classified differently in each directory.
In our next post, we use this directory-driven data as one source for
generating some market size and segmentation numbers.
Podfeed.net Podfeed.net is a podcast directory that helps you find podcasts, read and write podcast reviews, listen to podcasts and share your podcast with others.
EveryPodcast.com A broad selection of podcasts, with a lot of non-US titles.
Get A Podcast Relatively new site that claims to have 11,000+ users.
Podcast Blaster Helps everyone understand how easy it is to Podcast.
Podcast Fusion Quickly find podcast programming from anywhere on the internet. Bookmark your favorites and have them synchronized automatically to your MP3 player.
Amigofish A way of finding podcasts and videoblogs of interest to you. "Catch what you love."
GoldenFeed The RSS search engine. "Come find your feeds."
Digital Podcast Focuses on the convergence of brands, media and social technologies.
TiVo Podcasts Network-enabled TiVo machines have access to a wide variety of RSS-type content, including several of Sonibyte's popular podcasts.