Mobile apps generate a huge amount of data based on users’ in-app activity, from sessions and registrations to purchases and ads views. App developers are able to track and monitor all these post-install events by integrating with Mobile Measurement Partners (MMPs) such as Appsflyer, Adjust and Singular. By leveraging the data provided by these third-party companies advertisers can easily identify the most suitable mobile app KPIs which allow them to assess their performance and make data-driven decisions.
In this article, we’re going to explore which are the most important mobile app KPIs to track your app’s performance and also your app user acquisition efforts. Indeed, mobile app KPIs are often used to assess the performance of app install campaigns run by Demand-Side Platforms (DSPs) and AD Networks.
We’ve divided mobile app KPIs based on four stages within the user funnel inside the app: acquisition, engagement, retention and monetization.
Mobile App KPIs for Acquisition
Acquisition represents the first step user journey inside the app, and advertisers can evaluate their app user acquisition efforts by keeping track of several KPIs.
First of all, it is crucial to monitor how much you are paying to acquire a new user, especially when running app install campaigns. CPI, which stands for cost-per-install, is the price advertisers pay for each new user acquired through a paid user acquisition campaign, and when it is variable, it becomes an effective KPI to measure your spend on app user acquisition.
Secondly, app developers can track their equivalent CPI, a.k.a eCPI, which is the same as CPI, but it is computed as the ratio between the total cost of user acquisition and the number of new users. It is particularly relevant when you’re using different pricing models compared to CPI, such as CPA, CPC or CPM.
Then, many advertisers use CAC (Customer Acquisition Cost) amongst their mobile app KPIs for user acquisition activities. The difference between CAC and CPI is subtle and it assumes that not all users become customers, thus generating revenues for app developers. Therefore, advertisers know the post-install event which makes users become customers, based on data and machine learning predictions. It is then easy to compute such a metric by dividing the cost of user acquisition campaigns and the number of users who performed the selected post-install event.
Mobile App KPIs for Engagement
After having installed an app, users can often carry out a wide range of in-app events such as registrations, purchases, deposits or they can play levels of a mobile game. There are multiple metrics to assess how much users engage with the app, and such mobile app KPIs for engagement can also be used to optimize app install campaigns. Let’s take a look at some of the most popular:
- Monthly active users (MAU): this metric counts the number of users who open the app at least once a month or during a 30-day period.
- Daily active users (DAU): this mobile app KPI is the same as MAU but it is computed on a daily basis and even for specific days.
- Average session length: average session length measures how much time on average users spend in app.
Mobile App KPIs for Retention
Similarly to engagement, retention is an indicator of how much users are satisfied with the app, but it is measured in a different way. Indeed, retention measures satisfaction by counting the amount of users who return to the app, or leave, during a chosen time period. The two main mobile app KPIs for retention are retention rate and churn rate.
The former can be computed as the ratio between the number of active users in a specific time period (day, week, month) and the number of active users in the previous time period.
The latter measures is exactly the opposite of retention rate, as it measures the percentage of users who have stopped using the app after a selected time frame. Therefore, it can easily be computed as follows: 1 - retention rate.
Mobile App KPIs for Monetization
Last but not least, monetization often comes after engagement with the app and it happens either through in-app ads or in-app purchases. Advertisers usually assess how profitable their users are through two monetization mobile app KPIs, ARPU and LTV.
ARPU stands for Average Revenue Per User and it computes on average how much a single user spends in-app in a given period of time by dividing the total in-app revenues generated in the time period by the total number of active users for the same time.
LTV stands for Lifetime Value and it predicts the value generated by a user over his or her entire lifetime as a customer. App developers usually rely on software to predict user LTV by analyzing data generated by users such as app openings, average session length, number and value of in-app purchases, etc.