Subscriptions 101: learn how to get +23% app revenue Read more

(Customer) Churn

Number of paying customers who fail to become repeat customers and no longer use the product.

(Customer) Retention

The process of getting existing customers to continue purchasing your services or products.

(Mobile) Subscription

Renewable or auto-renewable product that grants the user access to certain features of the app for a limited period of time in exchange for a certain amount money.

(Paywall) A/B test or A/B testing

Randomized experimentation process where two or more versions of the paywall are shown to different segments of app users at the same time to determine which version leaves the maximum impact and drives business metrics.


Application Programming Interface, which is a software intermediary that allows two applications to communicate to each other.


Average Revenue Per Paying User. Metric that measures how much money a company earns for each paying customer.


Average Revenue Per User. Metric that shows the earnings generated per user or unit.


Annual Recurring Revenue. This metric is used to show the money that comes in every year for the whole life of a subscription (or contract).

Active subscription

The number of subscriptions that are currently active.

Active user

Unique users who access an app for a definite period of time.

Ad server

A platform for managing ad campaigns.


Short for mobile application.

App Store Connect

Platform created by Apple for developers which they use to publish their apps on the App Store.

App Tracking Transparency (ATT)

It’s a framework on iOS, iPadOS and tvOS that is used to ask an app users for permission to share their data.

App revenue

Income from the application.

App store optimization (ASO)

Process of optimizing the visibility of your app in an app store’s search results.


Process that includes identification of user events that contribute to a desired outcome and the vakue assignment to each of these events.

Auto-renewable product

Subscription product that is automatically purchased after the end of each billing period (each month, year, etc., depending on the access period granted by the product).

Billing Retry State

State, where the store attempts to collect the payment for up to 60 days from the user experiencing billing issues.

Billing issue

Situation when the user cannot renew their subscription because of certain problems, like invalid bank card info, issues with the bank, not enough money on the account, etc.

Click through rate (CTR)

The ratio of users who click on a specific link to the number of total users who view a certain page or screen in the app.

Click to install time (CTIT)

The time interval between when the user clicks on an ad and the app is opened for the first time.


Set of users grouped together because of a common characteristic.

Cohort analysis

Process of breaking a large group of users down into smaller segments with specified characteristics or features over a certain period of time.


Point at which a user performs a desired action.

Cost per action (CPA)

Pricing model in digital advertising that allows to charge an ad network only for a certain action taken by a customer (like purchase or registration).

Cost per click (CPC)

In online advertising, a model where an advertiser pays for every ad click made by a user.

Cost per engagement (CPE)

Pricing model in digital advertising where advertisers pay for ads within the app only after the user interacted with them in a specified way.

Cost per install (CPI)

An advertising metric used in mobile Internet marketing, which shows the cost of installing an application.

Daily active users (DAU)

A number of unique users that access an app within 24-hours.

Deep linking

Directing users to a specific page on the website or specific content in an app.

Device ID

A unique combination of numbers and letters associated with a specific device.

Eligibility/to be eligible

State of posessing certan criteria to be granted access to certain material, discount, features, etc.


Any activity in the app or the server that can be tracked.


Relatively new framework developed by Google which lets you quickly create cross-platform apps.


The way a potential customer goes through to purchae your good or service.

GAID (Google Advertising ID)

A unique advertising identificator provided by Google Play services.

Google Play Billing Library

Service that allows selling digital products and content in the Android apps.

Grace Period

Period between the end of a billing cycle and the date the next payment is due.

Identifier for vendors (IDFV)

A unique identificator assigned to all the apps of one developer.

Identity for advertisers (IDFA)

A unique advertising identificator provided by Apple for iOS devices.

In-app notifications

Messages that developers can send to users within their app.

In-app purchase (IAP)

Subscription or any other product that can be purchased from an app.

In-app subscription

Subscription product (usually auto-renewable) that can be purchased from an app.

Intro offer

Pricing option that the clients can only purchase one time. Usually offers a discount or free tiral.


(JavaScript Object Notation) is a text-based data exchange format. Used in Adapty to change paywall elements in an app throgh Remote config

Lifetime (subscription)

Same as Non-renewable. In theory, must be available to the user forever after the purchase.

Lifetime value (LTV)

Total revenue a customer will generate over the time of using a certain product or service.


Mobile Measurement Partner. Company that helps app developers check the campaign performance of their app through all advertising channels.


Monthly Recurring Revenue. It’s the Income a company can reliably predict every 30 days.


Monthly Tracked Revenue. It’s the amount of revenue tracked by Adapty (in USD, and before the platform cut) during a one-month billing period.

Monthly Active Users (MAU)

A number of unique users that access an app within 30 days.


A mobile app created exclusively for a single platform, built with the programming language and tools specific to this platform only (e.g. iOS or Android).

Non-organic install (NOI)

App install that took place because of marketing or advertising activities.

Non-renewable product

Lifetime product, purchased only once.

OTT (Over-the-top)

Content delivery directly to the user via Internet.

Organic install

App install that occurs when the user deliberatley installs the app they searched for.

Pay as you go

Introductory offer, where new subscribers pay an introductory price each billing period for a specific duration (for example, $1.99 per month for 3 months).

Pay upfront

Introductory offer, where new subscribers pay a one-time introductory price for a specific duration (for example, $1.99 for 2 months).


Screen/page in your app that offers the user to purchase one or more in-app products.


A process of sending by a mobile app data to external servers, usually the ones of marketing companies or ad networks.

Predicted lifetime value (pLTV)

Prediction of LTV based on historical data.

Private marketplace (PMP)

A private auction where premium publishers make their inventory available to select buyers only.

Production server

Server used for deploying and  hosting live websites or web apps.

Promo offer

Special commerical offer made to the user in order to persuade them to use or purchase something (usually in the form of discount).

Purchase validation

Process of confirming the act of purchasing of an in-app product.

Purchase/subscription implementation/integration

Process of inserting special code into your app that will enable you to sell purchasable in-app products.

Push notification

A pop-up message sent by a mobile app to the user.

React Native

Open-source UI software framework created by Meta Platforms, Inc., used to develop cross-platform apps.

Receipt validation

Protection means against fraudulent in-app purchases in the App Store and Play Market. Used to confirm that transactions were made correctly.


A chargeback for the purchase.

Return on ad spend (ROAS)

Metric that shows the amount of revenue generated from advertising.


Software Development Kit. It’s a set of software tools and programs used by developers to create apps for specific platforms.


Error codes for StoreKit errors.


Testing environment that emulates the true-to-life conditions.


Category of customers who share similar charachteristics.

Server notifications

Server-to-server service that notifies you in real time when the status of in-app purchases and refunds changes.


Happening in the server, not in the app.

Shared secret

Special key to receive receipts for auto-renewable in-app subscriptions.

Split-test or Split-testing

Same as A/B test.


Framework that allows purchasing digital goods or services in the apps across all Apple platforms.

Process of returning the money spent by the user on buying an in-app purchase. Usually comes along with the revocation.

Subscription renewal

Extending the access to the subscription features for the next period.

Subscription revocation

Process of cancelling the user’s subscription by the developer.

Subscription/renewal cancellation

State when the user is unwilling to pay and calls off the subscription. Also occurs as a result of billing issues.

Trial/Free trial

Introductory offer, where new subscribers access content for free for a specified duration. Subscriptions begin immediately, but subscribers won’t be billed until the free trial period is over.


Cross-platform game engine.

User acquisition (UA)


A method on the web that allows apps and services to send a web-based notification to other apps whenever a specific event occurs.