Glossary of MoPub Terms

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ad requests

This is the number of times an app requests an ad to load.

ad unit

Ad placement in a mobile app used to display ads to the app users in order to monetize traffic.

ad unit ID

A MoPub-specific ID that provides a unique serial number for each ad unit. This ID can be found in the URL (for example, and in the Apps tab’s Ad Unit page, by clicking Edit ad unit → View code integration.


Snippet of code that bridges the communication between the MoPub SDK and other SDKs. Find the adapters for MoPub-supported networks here. Implementation is as easy as copying the scripts in your Gradle/Cocoapods projects.

Advanced Bidding

Advanced Bidding is MoPub’s reimagination of header bidding adapted to the mobile app ecosystem. AB replaces the traditional linear waterfall with simultaneous real-time bidding, increasing efficiency. Find more information here.

Android Studio

Android Studio is the official integrated development environment (IDE) for Google’s Android operating system, built on JetBrains’ IntelliJ IDEA software and designed specifically for Android development. It is available for download on Windows, macOS, and Linux-based operating systems. To learn how to get device logs through Android Studio, refer to our instructions.


An application; in the context of the MoPub UI, an app is downloaded by a user to a mobile device.

app store URL

A link that redirects to the app page of an app published in the app store.


Average revenue per user (ARPU) is calculated as total revenue divided by the number of unique users.


This is the number of times any demand source (or ad source) is called to fill an ad request. A given ad request can attempt multiple ad sources. For example, an ad unit’s waterfall may have three networks. An app makes an ad request and Network 1 is ‘attempted’ for an ad, but they have no ad to serve. Network 2 is attempted for an ad and is able to fill the request. In this scenario, there was 1 ad request, 2 network attempts, and 1 impression.

Auto CPM

Auto CPM automates the task of updating network CPMs in the ad mediation waterfall to accurately reflect the CPM that your demand sources are paying for your ad inventory. Find more information here.

average session duration

The average amount of time spent by users in a given app.

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bidder seat

A DSP uses a bidder seat on an ad exchange to participate in a real-time bidding (RTB) marketplace. Similar to seats on equities exchanges, bidder seats signifiy a direct relationship between advertisers and the ad exchange, and a single seat can represent multiple media buyers. A bid response to a bid request in an auction contains the buyer’s Seat ID, along with other essential bidding information.

bundle ID

A bundle identifier uniquely identifies an application in the apps ecosystem. This data is important and is used by DSPs to validate the authenticity of an app. MoPub extracts this information from the app store URL, provided that it is properly entered in the MoPub UI.

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Process of pre-loading and storing ads in a cache in order to have them ready to display to a user.

Charles log

Charles Proxy is an HTTP/HTTPS traffic viewer you can use to view the traffic between your device and the Internet. Because the MoPub SDK uses HTTP/HTTPS to request and receive ads, you can use Charles for debugging, and to test apps’ ad requests, responses, and creative-level information. Learn more about it here.


CocoaPods is a library dependency management tool for OS X and iOS applications. With CocoaPods, you can define your dependencies, called pods, and manage their versions easily over time and across development environments. To integrate MoPub through CocoaPods, refer to our instructions.


The Children’s Online Privacy Protection Act (COPPA) is a law created to protect the privacy of children under the age of 13. The Act was passed by the U.S. Congress in 1998 and took effect in April 2000. COPPA is managed by the Federal Trade Commission (FTC). Only COPPA-compliant apps can monetize through MoPub. Find more information in our Supply Partners Policies.


The cost per click (CPC) is the price DSPs pay for one click (usually a click on an ad) in a CPC campaign.


Cost per mille (CPM) is the cost per thousand impressions. It is a common fee structure and denotes the price a DSP pays upon the thousandth impression.


Click-through rate (CTR) is the ratio of clicks over impressions.

custom event

Custom events support ad network SDKs for networks not listed on our Supported Mediation Partners. MoPub discourages using non-supported network adapters and does not provide testing or technical support for issues arising from their use.

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Daily average users (DAU) is the number of unique devices that create one or more ad requests broken down by day (MoPub records all information in UTC time).


Different ad sources willing to pay to access a given in-app inventory.

device log

Device logs contain events logged by the SDK, ad server, and network adapter. Device logs may contain information about the cause of some errors. Learn more about device logs on Android or iOS.

direct deals

Campaigns reflecting deals that are typically closed directly with agencies and advertisers. They can be trafficked through MoPub by creating an order and then a Guaranteed Line Item through the Orders tab.


Demand-side platforms (DSPs) are the companies that advertisers and agencies use to buy ad inventory programmatically. DSPs use data and artificial intelligence to determine which inventory to bid for on behalf of the buyer. DSPs use a bidder seat to bid on impressions in the exchange.

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Effective Cost per Mille (eCPM) is calculated as (total earnings / total number of impressions) X 1000, regardless of what buying method is being used (fixed price, CPM, CPC, CPA or CPO). For example, CPI campaigns, which pay only on install, must be converted to the same terms for an apples-to-apples comparison. The main difference between CPM and eCPM is the data you use to calculate it.


Exchanges are platforms that facilitate the buying and selling of ad space in a marketplace environment. This is where the real-time auctions are hosted, connecting publishers with buyers who want to bid on their ad inventory.

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Failover is the practice of passing the impression opportunity back to be filled by another eligible demand source in the case of no fill. Within the context of MoPub a demand source will failover back to MoPub for proper mediation based on the waterfall setup for the ad unit.

fill rate

MoPub fill rate refers to the number of impressions divided by the number of ad requests. Note that this often differs from network fill rates, because networks use different formulas to calculate fill rate.


In the context of the MoPub UI, ad formats are defined by the size and creative attributes of the ad space in your app. Ad formats accepted by MoPub are: banners, medium rectangles, native, native video, interstitial (static, playables, and video), and rewarded video.

frequency capping

Capping refers to restricting the number of times, or frequency, a specific visitor to an app is shown a particular ad. You can set frequency capping at the ad unit level or at the line item level in the MoPub UI.

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The General Data Protection Regulation (GDPR) is a legal framework that sets guidelines for the collection and processing of personal information of individuals within the European Union (EU). GDPR came into effect across the EU on May 25, 2018. To find more on MoPub’s approach to GDPR check our FAQ and the publisher SDK integration guides for Android or iOS.

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HTML tag

Hypertext Markup Language (HTML) elements are represented by tags. HTML tags label pieces of content in ads.

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impression counting

Approach for counting impressions based on triggered events. MoPub’s counts an event as an impression when at least one pixel is on screen.


A performance metric, this is the number of times an ad shows on screen.

interstitial ads

Interstitial ads are fullscreen ads that cover the interface of their host app. They’re typically displayed at natural transition points in the flow of an app, such as between activities or during the pause between levels in a game.

invalid traffic (IVT)

Invalid traffic (IVT) is any activity that doesn’t come from a real user with genuine interest. It can include fraudulent impressions, clicks, or app downloads caused by faulty ad implementations.

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JavaScript (JS)

JavaScript is a programming language commonly used in web development. JavaScript code can be inserted anywhere within the HTML of a web page.

JavaScript tag, JS tag

The <script> tag is used to define a script (JavaScript). The <script> element either contains scripting statements, or it points to an external script file through the src attribute. Common uses for JavaScript are image manipulation, form validation, and dynamic changes of content. Although MoPub accepts JStag network mediation, we caution its usage. Learn more about these tags here.

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Keywords contain user- or app-level information that can be passed through the SDK for advanced targeting in line items. Learn more about them here.


Kotlin is a cross-platform, statically typed, general-purpose programming language with type inference. It interoperates fully with Java, is officially supported by Google for mobile development on Android, and is included as an alternative to the standard Java compiler.


Type of performance metric. Key Performance Indicators (KPIs) measure the success of a particular activity in a given context.

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line item

Line items enable publishers to create campaigns targeting specific ad units and ad sources. Line Items can be set at any priority level to allow publishers prioritze specific campaigns. Line items offer advanced targeting capabilities. Line item types include Marketplace, Guaranteed (usually for direct deals), Backfill and Network.

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MoPub Marketplace is our real-time bidding (RTB) exchange, which gives publishers access to an additional revenue source through a competitive auction with complete transparency and control. MoPub’s Marketplace will only win if it is able to beat the highest performing ad network that has an available ad. Marketplace increases the quantity of potential bidders for your impressions, without having to include additional SDKs. Learn more here. In the MoPub UI, the Marketplace tab enables publishers to manage Marketplace settings.


Monthly average users (MAU) is the number of unique devices that create one or more ad requests, broken down by month (MoPub records all information in UTC time).

mediation stack

The list of demand sources included in a waterfall targeted to a specific ad unit. The ad networks in the stack are ranked by priority level first, then CPM (within that priority). Through the waterfall process, an ad request will “attempt,” or ask each demand source for an ad to serve, and continue down the waterfall until an impressions is served.


MoAnalytics is a data analytics tool reserved for managed publishers. Learn about it here.

MoPub report

MoPub reports track performance based on MoPub data and include Marketplace revenue. Find more information here.

MoPub Sample App

The MoPub Sample App is for anyone who has a stake in how a creative or tag functions in a MoPub-integrated app, or who wants to use a reference for implementation to troubleshoot possible MoPub-SDK integration issues. Find Android and iOS versions here and Unity here.


Mobile Rich Media Ad Interface Definitions (MRAID) is a framework for mobile advertisers and publishers that allows rich media ad creatives to run across all compliant devices and applications. It is a standard developed by the Interactive Advertising Bureau (IAB) in late 2011. MRAID is designed for publishers who want to do direct sales with more engaging ads as well as those who want to work with ad networks that support rich media creatives.

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An ad network connects advertisers to apps in order to serve ads. Networks do not bid in real time, with the exception of those who are participating in Advanced Bidding. Publishers can manage mediated networks in the Networks tab.

network allocation

This feature can be used to dictate the percentage of ad requests a network should receive daily.

network eCPM

The cost per thousand impressions for a network is the average CPM for a given network or network line item. In the MoPub UI, the Network eCPM is not a price floor; it is an indicator used to rank the order of the calls in the waterfall. The value should be updated regularly (manually or via Auto CPM) to reflect the average eCPM the network is paying for that ad unit. See also eCPM.

network mediation

Network mediation enables MoPub publishers to make ad requests to multiple ad networks to maximize revenue and increase fill rate. MoPub supports both server-side and client-side network mediation integrations. We encourage publishers to mediate networks included in the list of supported mediation partners.

network report

Network reports track performance data from the supported networks in this list, and include network revenue data. Note that this data is directly pulled from the network.

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optimization, optimizing

Actions taken in order to improve the performance of an ad unit, app, or account. The goal is usually to boost performance and reduce inefficiencies, such as latency.


An option to manage your inventory by creating line items. In MoPub, an order is a grouping of line items.

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price floor

Minimum bid that you are willing to accept for the DSPs’ to access to your inventory. We recommend that you set your Marketplace price floors to be lower than your lowest network CPM to maximize Marketplace competition and yield.


Sytem to prioritize demand source by ranked groups within the waterfall. There are 16 priorities within the MoPub waterfall, with 1 being the highest and 16, the lowest. If the inventory isn’t sold in the first priority sent, it will failover to the following priority until it fills.

privacy policy

A privacy policy is a statement or a legal document that discloses some or all of the ways a party gathers, uses, discloses, and manages a customer’s or client’s data. It fulfills a legal requirement to protect a customer’s or client’s privacy. MoPub requires publishers to have a published Privacy Policy in your app page to obtain Marketplace approval. Find more information in our Supply-Side Partner Policies.


ProGuard is a free Java class file shrinker, optimizer, obfuscator, and preverifier. It detects and removes unused classes, fields, methods, and attributes. It optimizes bytecode and removes unused instructions. You can use it to integrate MoPub. Learn more here.

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refresh rate

The refresh rate interval is the number of seconds an ad will display on screen before a subsequent ad request is made for a new ad. For example, if you set a refresh interval of 30 seconds, the next ad request will occur 30 seconds later.


Performance data consolidated in offline spreadsheets.


Total amount of earnings generated from in-app advertising activity. Recommendation: Use offline reports, where data has been consolidated, to track your revenue.


With real-time bidding (RTB), in-app inventory is bought and sold in a live auction system where advertisers bid on each impression in real time the moment you request an ad.

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sample app

The MoPub Sample App is for anyone who has a stake in how a creative or tag functions in a MoPub-integrated app, or who wants to use a reference for implementation to troubleshoot possible MoPub-SDK integration issues. Find Android and iOS versions here and Unity here.


The MoPub software development kit (SDK) contains the necessary tools to enable monetization of apps. Refer to our instructions for integrating the Android SDK, the iOS SDK, and the Unity Plugin.


A segment is a slice of your network inventory with specific apps or ad units that can be targeted to specific countries and networks. It is a combination of three variables: 1. apps or ad units, 2. ad networks, and 3. geography (based on one or more countries). In the MoPub publisher UI, the Segments tab enables publishers to manage network activity in Priority 12.

server-to-server (S2S)

A server-to-server (S2S) connection is a connection between the MoPub server and another server, usually an ad network’s. Refer to our list of networks with S2S connections to MoPub.


The singleton method enables you to show the same ad impression as users navigate through various screens of your app. It involves creating an object with the MoPub ad view, allocating the object to the active view, and then de-allocating it and reallocating it to each view as the user navigates within the app. Find more information in our documentation.


Supply-side platforms (SSPs) provide a way for publishers to sell their inventory on exchanges;
they’re the inverse of DSPs. MoPub is an SSP.

supported network

A MoPub-supported network is a network with a supported SDK integration. Review the list of supported networks here. Make sure to work with the supported instance when integrating a network included in the list.


Swift is a general-purpose, multi-paradigm, compiled programming language developed by Apple Inc. for iOS, macOS, watchOS, tvOS, Linux, and z/OS. Swift is designed to work with Apple’s Cocoa and Cocoa Touch frameworks and the large body of existing Objective-C code written for Apple products.

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App traffic is the amount of data sent and received by users in the app. App traffic is measured through app activity, such as opening the app, number of sessions, session duration, and ad requests.

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User interface provided by MoPub for accessing the MoPub Services.


The number of unique devices that create one or more ad requests. Note that this figure doesn’t include ‘Do Not Track’ users.


Unity is a cross-platform real-time engine developed by Unity Technologies. It is an OS X-exclusive game engine.

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valid store URL

A valid store Uniform Resource Locator (URL) is a complete web address used to find a particular app page in the app store. MoPub requires publishers to have a valid store URL (for published apps) to obtain Marketplace approval. Find more information on Marketplace approval here.


Video Ad Serving Template (VAST) is a specification released by the Interactive Advertising Bureau (IAB) that sets a standard for communication requirements between ad servers and video players. It is a data structure declared using XML. Find more information on how to set up Direct VAST campaigns on MoPub here.


Viewability tracks the impressions seen by users. Learn more about how MoPub supports viewability on Android and iOS.

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System to organize demand source calls in order to fill an ad unit’s inventory. Through the waterfall process, an ad request attempts, or asks, each demand source for an ad to serve, and continues down the waterfall until an impression is served.

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The integrated development environment (IDE) from Apple that is used to create, compile, and test Mac OS X and iOS (iPhone/iPad/iPod) applications. Refer to our instructions for integrating MoPub through XCode.

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Last updated January 09, 2020

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