Session

What is a Session?

- mobile app session is recorded each time a user opens and interacts with an app. It is one of the most direct indicators of user engagement you have. High session counts suggest users are returning to your app regularly and finding value in it. Low or declining sessions can be an early warning sign of churn.

Sessions are typically reported to a mobile measurement partner (MMP) and tied to user-level data, which means you can analyze them by cohort, channel, or campaign. This makes session tracking useful not just for product teams, but for marketers trying to understand the downstream quality of the users they are acquiring.

How Session Tracking Works

Session tracking is triggered when a user opens the app. The session is recorded and sent to your MMP or analytics platform, where it is logged against that user's profile and associated campaign data.

A new session is typically counted when:

• A user opens the app after it has been fully closed
• A user returns to the app after a defined period of inactivity (usually 30 minutes, though this threshold can vary)

The session ends when the user closes the app or moves it to the background long enough to trigger the inactivity timeout.

Accurate session tracking depends on your SDK being correctly integrated and your inactivity thresholds being configured in a way that reflects real user behavior in your app category.

Why App Sessions Are Important

Sessions sit at the intersection of engagement, retention, and revenue. Here is why they deserve attention across your whole team:

Engagement and Retention Signals 

Session frequency and length tell you whether users are sticking around after installing. A user who installs and never opens the app again registers zero sessions after the install event. Tracking sessions over time reveals retention patterns that install data alone cannot show.

Revenue Correlation for IAA 

For apps monetized through 主にアプリ内広告（IAA）, sessions are directly tied to revenue. More sessions mean more ad impressions, which means more ad revenue. This positive correlation makes session volume one of the most commercially important metrics for IAA-focused developers. Understanding your session trends helps you forecast revenue and identify drops before they affect your bottom line.

Product Improvement 

Low session counts or declining average session length can point to specific problems in your app experience. Whether it is a frustrating onboarding flow, a difficulty spike in a game, or a feature that is not landing, session data gives product teams the signal to investigate.

User QA

Not all installs produce engaged users. Session tracking helps you evaluate the quality of users coming from different campaigns and channels. A campaign that drives high install volume but low subsequent sessions is delivering low-quality users, even if the CPI looks attractive.

Key Session Metrics to Track

What Are CPM N-Day Sessions?

CPM N-day sessions is a metric used to measure the cost efficiency of acquiring users relative to their session behavior over a defined number of days (N).

At Tenjin, CPM N-day sessions are calculated as:

1,000 x Total Spend / Total App Opens on N-Day

This metric is particularly useful for IAA apps because it connects your acquisition spend directly to the session activity that drives ad revenue. Instead of just looking at cost per install, CPM N-day sessions help you understand how much you are paying per thousand sessions generated by users acquired through paid campaigns. It is a more complete picture of UA efficiency for session-driven monetization models.

Sessions vs. Other Engagement Events

Sessions wrap around in-app events. A single session can contain multiple in-app events, which is why session length and depth both matter when evaluating user quality.

How Tenjin Tracks App Sessions

Tenjin gives you clear visibility into session data without the complexity of building your own analytics infrastructure around it.

With Tenjin, you can:

• Track session volume and frequency across your entire user base
• Analyze sessions by cohort, campaign, and channel to assess user quality
• View CPM N-day session data alongside spend and revenue metrics
• Export raw session data via DataVault or Raw Data Exporter for deeper analysis
• Connect session trends to LTV and pLTV models for smarter forecasting

Related Terms

• インストール
• Attribution Window
• Cohort Analysis
• Cost Per Install (CPI)
• デイリーアクティブユーザー(DAU)
• In-App Advertising (IAA)
• Mobile Measurement Partner (MMP)
• Retention Rate

よくある質問 

What is an app session?

An app session is a single instance of a user opening and actively engaging with a mobile app. It begins when the app is opened and ends when the user leaves or the app becomes inactive for a set period of time.

Why is session tracking important?

Session tracking tells you how frequently and deeply users are engaging with your app after installing. For IAA apps, sessions are directly tied to ad revenue. For all apps, session data is a key signal for retention, user quality, and product health.

What are CPM N-day sessions?

CPM N-day sessions measure the cost efficiency of acquiring users relative to their session activity over a defined number of days. At Tenjin, it is calculated as: 1,000 x Total Spend / Total App Opens on N-Day. It is especially useful for IAA apps connecting spend to session-driven revenue.