In December 2008 I collected the subscriber data of 6 YouTube Channels from the Most Subscribed Top-100 list, in total 478,903 data sets. I analyzed the data to find out how many subscribers were still active in relation to the median age of each subscriber base. I posted the results earlier last year.
In December 2009, one year later, I revisited all subscribers from December 2008 and updated the collected data. This allows for a year-by-year comparison of nearly 500,000 subscribers. In addition to Log-In time and Account Status, I also verified the Subscription Status of each subscriber. This reveals the number of users who unsubscribed, a figure that is not listed anywhere on YouTube. In order to see how many inactive subscribers returned to an active state (and vice versa), I added two additional charts for each Channel. As a reminder: Active subscribers are those with log-in times under 4 weeks and the Median Age refers to the date when a Channel reached 50% of its current subscribers.
The most interesting result is the yearly decay rate of active subscribers. For all six Channels this rate lies between 22% and 26%. Considering the differences in Median Age and Subscribers, this narrow range is pretty interesting. While some of the six Channels quadrupled their subscribers in 2009, others barely grew at all. Similar differences apply for the activity of a Channel: One of the analyzed Channels only released a single video in 2009.
These results support the presumption that every Channel on YouTube looses roughly 25% of their active subscribers each year, regardless of activity or popularity. Those Channels that grew massively and released new videos regularly couldn't keep substantially more of their old subscribers than those Channels that released only a few videos within the last year.
Detailed Results
With the help of some math we can use the decay rate to calculate the mean lifetime of a subscriber and the half-life of a subscriber base. Compared to the calculations based on the median age in my first blog post (Half-Life = 26 Months), the numbers are now based on a closed subscriber base that doesn't grow anymore (Half-Life = 31 Months). With a linear offset, the new decay function fits nicely into last year's "active subscribers vs. median age" plot.
On an average the results of this year-by-year comparison are the following:
- Users who unsubscribed: 4.7%
- Decay of active Subscribers: 24%
- Mean Lifetime of a Subscriber: 3 Years and 10 Months
- Half-Life of a Subscriber Base: 2 Years and 7.5 Months
Some details on the retention rate:
- 69% of active subscribers remained active
- 56% of subscribers with log-in times under 48 hours remained in this category
- 15% of inactive subscribers returned to an active state
- 8% of subscribers with log-in times over 1 year returned to an active state
Here are the 2008/2009 comparison charts for the 6 Channels: