Ad Monetization Glossary
Every term you'll encounter when monetizing a mobile app with ads.
A
Ad Caching
Storing ad creatives on the device before they're needed so they can be displayed instantly when a placement triggers. Reduces latency and improves fill rates.
Ad Exchange
A digital marketplace where advertisers and publishers buy and sell ad inventory through real-time auctions. Examples include Google Ad Exchange, DT Exchange, and InMobi Exchange.
Ad Format
The type of ad displayed to the user. Common mobile formats include banners, interstitials, rewarded ads, native ads, app open ads, and rewarded interstitials. Each has different revenue characteristics and user experience trade-offs.
Ad Impression
A single instance of an ad being displayed to a user. Impressions are the basic unit of measurement for ad revenue. One ad view = one impression.
Ad Mediation
The process of managing multiple ad networks through a single integration point. A mediation layer decides which network serves each impression, typically through a waterfall, in-app bidding, or a combination of both.
Ad Network
A company that connects advertisers with publishers. Ad networks aggregate ad inventory from publishers and sell it to advertisers. Examples: Google AdMob, AppLovin, Meta Audience Network, Unity Ads, Chartboost.
Ad Request
A call from the app to an ad network or mediation layer asking for an ad to display. If the request returns an ad, it's a fill. If not, it's a no-fill.
Ad Unit
A specific placement in your app where ads appear. Each ad unit has a unique identifier and is associated with a particular ad format.
App Open Ad
A full-screen ad format that displays when a user opens or returns to your app. Designed for the app launch or foreground transition — shows between the loading screen and the main content.
ARPDAU (Average Revenue Per Daily Active User)
Total ad revenue divided by daily active users. The most important metric for comparing monetization performance day over day. Higher ARPDAU means you're earning more from each user session.
ARPU (Average Revenue Per User)
Total revenue (ads + IAP) divided by total users over a period. Unlike ARPDAU, ARPU looks at a broader window (weekly, monthly) and includes all revenue sources.
B
Banner Ad
A rectangular ad displayed at the top or bottom of the screen, typically 320x50 or 300x250 pixels. Banners are always visible during gameplay or app usage. Lowest revenue per impression but highest impression volume.
Bid
An offer from an advertiser or ad network to pay a specific price for an impression. In real-time bidding, multiple networks submit bids simultaneously and the highest bid wins.
Bid Density
The number of active bidders competing for a given impression. Higher bid density generally leads to higher eCPMs because more competition drives prices up.
Bid Shading
A practice where a bidding platform reduces its bid below what it would otherwise pay, taking advantage of auction mechanics. This can reduce publisher revenue in opaque auction environments.
C
Click-Through Rate (CTR)
The percentage of ad impressions that result in a user tap/click. CTR = clicks / impressions. Higher CTR indicates more engaging ad creatives.
CPA (Cost Per Action)
The price an advertiser pays when a user completes a specific action after seeing an ad (e.g., installs an app, makes a purchase). Used primarily in performance advertising.
CPC (Cost Per Click)
The price an advertiser pays for each click on their ad. Less common in mobile app monetization than CPM, but used for some performance campaigns.
CPM (Cost Per Mille)
The price an advertiser pays per 1,000 impressions. This is the buy-side metric — what advertisers spend. See also eCPM for the publisher-side equivalent.
Creative
The actual ad content shown to the user — an image, video, playable demo, or HTML element. Creative quality directly affects CTR and user experience.
Cross-Promotion
Advertising your own apps within your other apps. A free way to drive installs across your app portfolio without spending on paid UA.
D
Demand Source
Any entity willing to pay to show ads to your users. Ad networks, DSPs, and direct advertisers are all demand sources. More demand sources competing for your inventory means higher eCPMs.
DSP (Demand-Side Platform)
A platform that lets advertisers buy ad inventory programmatically across multiple ad exchanges and networks. Advertisers use DSPs to target specific audiences at scale.
E
eCPM (Effective Cost Per Mille)
The revenue a publisher earns per 1,000 impressions. eCPM = (total ad revenue / total impressions) x 1,000. This is the most important metric for comparing ad network and format performance. Higher eCPM = more revenue per impression.
F
Fill Rate
The percentage of ad requests that result in an ad being served. Fill rate = filled requests / total requests. A 90% fill rate means 10% of your ad requests go unfilled.
Floor Price
The minimum eCPM a publisher is willing to accept for an impression. Ads that bid below the floor are rejected. Setting floors too high reduces fill rates; setting them too low leaves money on the table.
Frequency Capping
Limiting the number of times a specific ad or ad format is shown to a single user within a time period. Prevents ad fatigue and protects user experience.
H
Header Bidding (In-App Bidding)
An auction method where multiple demand sources bid simultaneously for each impression, rather than being called sequentially in a waterfall. Results in higher eCPMs because all bidders compete at once. Also called parallel bidding or unified auction.
I
IAP (In-App Purchase)
Revenue from selling virtual goods, subscriptions, or premium features within the app. IAP and ad revenue are the two primary monetization models for mobile apps. Many apps use both.
Impression-Level Revenue Data (ILRD)
Revenue data reported at the individual impression level rather than aggregated. ILRD lets you attribute exact revenue to specific users, sessions, and placements — critical for LTV calculations and UA optimization.
Interstitial Ad
A full-screen ad that covers the entire app interface, typically shown at natural transition points (between levels, after completing an action). Higher eCPMs than banners but more disruptive. Best shown at natural break points, never mid-action.
Inventory
The total available ad impressions a publisher has to sell. Your inventory is determined by your DAU, session length, and number of ad placements.
L
Latency
The time between requesting an ad and displaying it to the user. High latency means slow-loading ads, which reduces viewability and fill rates. Predictive pre-loading eliminates latency by having ads ready before they're needed.
LTV (Lifetime Value)
The total revenue a user generates over their entire time using the app, including both ad revenue and IAP. LTV is the key metric for evaluating UA spend — you want LTV to exceed your cost of acquiring each user.
M
MMP (Mobile Measurement Partner)
A third-party platform that tracks app installs, in-app events, and attribution. MMPs connect your ad spend to actual user acquisitions. Examples: AppsFlyer, Adjust, Branch, Singular, Kochava.
MREC (Medium Rectangle)
A 300x250 ad format that fits within content layouts. Larger than a standard banner, often used in feeds or between content sections. Higher eCPMs than standard banners.
N
Native Ad
An ad that matches the visual design and layout of the app content around it. Native ads blend into the user experience rather than looking like traditional advertisements. Requires more implementation work but typically has higher engagement and eCPMs.
Network Neutrality (in mediation)
When a mediation platform has no financial incentive to favor one demand source over another. Platforms that operate their own ad network have a conflict of interest.
No-Fill
When an ad request does not result in an ad being served. Causes: no advertiser willing to pay above the floor price, geographic targeting mismatches, or demand source timeouts. High no-fill rates reduce your revenue.
O
Offerwall
An ad format that presents a list of offers (install an app, complete a survey, watch a video) in exchange for in-app rewards. Common in gaming apps. Users actively choose to engage, making it opt-in like rewarded ads.
P
Placement
A specific location and context in your app where an ad can appear. Examples: "home screen banner," "post-level interstitial," "store rewarded video." Each placement has its own performance characteristics.
Playable Ad
An interactive ad format that lets users try a mini-version of a game or app before installing it. High engagement rates and typically higher eCPMs than static formats.
Programmatic Advertising
Automated buying and selling of ad inventory through software, as opposed to manual direct deals. Most mobile ad transactions are programmatic.
R
Real-Time Bidding (RTB)
An auction that happens in milliseconds when an ad impression becomes available. Advertisers bid in real time based on the user, context, and placement. The highest bid wins.
Revenue Lift
The percentage increase in ad revenue after making a change (switching mediation platforms, adding demand sources, optimizing placements).
Rewarded Ad (Rewarded Video)
A full-screen video ad that users opt into watching in exchange for an in-app reward (extra lives, virtual currency, premium content). Highest eCPMs of any standard format because users actively choose to engage. Best practice: never gate core functionality behind rewarded ads.
Rewarded Interstitial Ad
A full-screen ad that combines the interstitial format with an opt-in reward. Unlike standard rewarded ads, rewarded interstitials can appear at natural transition points without the user explicitly choosing to watch. The reward is a bonus rather than a requirement.
S
SDK (Software Development Kit)
A package of tools, libraries, and documentation that lets you integrate a service into your app. Ad network SDKs handle ad loading, rendering, and tracking.
Session Depth
How far into a session a user is — measured by time spent, screens viewed, or actions completed. Deeper sessions typically generate more ad revenue because users see more placements.
Show Rate
The percentage of loaded ads that are actually displayed to users. Show rate = shown ads / loaded ads. A low show rate means you're loading ads that never get shown — wasting bandwidth and potentially letting high-value bid tokens expire.
SSP (Supply-Side Platform)
A platform that helps publishers manage and sell their ad inventory programmatically. SSPs connect to multiple ad exchanges and DSPs to maximize fill rates and eCPMs.
U
Unified Auction
An auction where all demand sources compete simultaneously for each impression, as opposed to a sequential waterfall. Results in higher eCPMs because the true highest bidder always wins. See also Header Bidding.
V
Viewability
The percentage of ad impressions that were actually seen by users. Industry standard: an ad is "viewable" if 50%+ of its pixels are on screen for at least 1 second (2 seconds for video).
W
Waterfall
A sequential method of requesting ads from multiple networks, one at a time, in order of expected eCPM. If the first network doesn't fill, the request passes to the second, and so on. Waterfalls are being replaced by in-app bidding because they're static — a network lower in the waterfall might have paid more but never gets the chance to bid.
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