Each SDK may gain or lose installs over a specified period of time. The percent of the SDK install base that gets uninstalled is what we call churn.
SDK Churn Rate shows the level of volatility for each devkit. A high churn rate indicates extreme changes in recent months. A low churn rate suggests that the SDK enjoys a stable user base.
How is SDK Churn Rate calculated?
MightySignal calculates SDK Churn Rate over a period of one month. To do this, we use two figures:
- Current installs at the start of the month
- Number of uninstalls during the month
Churn rate is the ratio of the two expressed as a percentage. Here's an example of how that might look:
- App Magic SDK has 1,000 installs on March 1
- App Magic SDK had 100 uninstalls between March 1 and March 31
- App Magic SDK had 50 installs between March 1 and March 31
In this example, the SDK Churn Rate is the uninstalls divided by the initial figure, or 100/1000. The rate is a percentage, so we say the SDK Churn Rate is 10%. Note that the number of installs during the period is irrelevant to the churn rate calculation.
On the MightySignal, this information appears under the public SDK profile's current installs chart, in the following format:
"App Magic SDK is currently installed in 1,100 apps. As of [six months ago], it was installed in 1,000 apps. That is a change of 10% over six months." You can use this information to deduce a churn rate.
Is SDK Churn Rate consistent across platforms?
No. SDK Churn Rate varies between iOS and Android due to user and developer behaviors.
An in-depth analysis revealed some interesting facts about churn on both platforms:
- Android apps have an average install length of 472 days
- iOS apps have an average install length of 450 days
- Lowest churn on Android is in the following SDK categories: user engagement, social, media, OCR, UI
- Lowest churn on iOS is in these SDK categories: VoIP, backend, customer support, OCR, app platform
- App categories with the lowest SDK churn rate on Android were sports, travel & local, food & drink, maps & navigation, and business
- App categories with the lowest SDK churn rate on iOS were developer tools, weather, magazines and newspapers, medical, and news
- iOS churn is higher on apps with a weak user base
- But Android churn is higher on apps with a strong user base
This variation shows why it's so valuable to study installs and uninstalls for each SDK. Volatility can occur anywhere in the app ecosystem, and something that's stable in one context could have a high churn rate elsewhere. For SDK developers that are looking for opportunities, the SDK Churn Rate can reveal surprising information about where developers are most likely to experiment.