Turn a searched term into an operating decision.
From CPA, ROAS, CTR, and LTV to attribution and incrementality — definitions, formulas, and the data to review next.
Turn this question into a decision
Every guide and definition leads to a matching free analysis tool. No sign-up; raw data stays in your browser.
See what actually moved performanceNarrow the cause with channel, campaign, and creative contributions.Analyze performance change →Find creative fatigue and swap priorityIdentify what to replace and what to produce next.Analyze creative fatigue →Start with the weekly movement mapUse a darker-is-newer path to spot repeated opposite movement, then continue to detailed diagnosis when needed.Open movement map →Know where the next dollar belongsSimulate channel scale-ups and pull-backs with marginal CPA, ROAS, and headroom.Plan budget allocation →Review CPA, ROAS, and pacing togetherUse one CSV to check the weekly operating state and anomalies.Open operations dashboard →Holdout and pre/post incrementalityEstimate what advertising added beyond attributed conversions.Analyze incrementality →
Adstock
The lingering effect of an ad that carries over after it stops running
ARPU (Average Revenue Per User)
Revenue over a period divided by the total number of users
ASO (App Store Optimization)
Improving search visibility and install conversion inside the app stores
ATT (App Tracking Transparency)
The iOS system prompt asking consent to track across apps — declining removes IDFA access
Attribution
The rule that decides which ad touchpoint gets credit for a conversion that happened
Attribution Window
How many days after an ad touch a conversion still counts toward that ad
CAC (Customer Acquisition Cost)
Cost of acquiring one customer — total acquisition spend divided by customers acquired
Cannibalization
When paid ads steal conversions that would have happened organically anyway
Click Injection
Fraud that fires a fake click right before install to steal attribution credit
Cohort
A group of users who all started (installed/signed up) at the same time
Conversion Value
The narrow value SKAN returns — early post-install behavior has to be compressed into it
CPA (Cost Per Action)
Cost per desired action (signup, purchase) — spend divided by conversions
CPC (Cost Per Click)
Cost per click — equal to CPM divided by CTR
CPI (Cost Per Install)
Cost per app install — total spend divided by number of installs
CPM (Cost Per Mille)
Cost per 1,000 impressions — the closest metric to raw media cost
Creative Fatigue
Response cooling as the same people see the same creative repeatedly — frequency rises while CTR falls
Crowd Anonymity (Privacy Threshold)
Apple returns less detail when install volume is small — below the tier, the fine value stops arriving
CTR (Click-Through Rate)
Share of impressions that got clicked — clicks divided by impressions
Custom Product Page (CPP)
An Apple feature for building multiple product pages for one app and serving them by traffic source
CVR (Conversion Rate)
Share of clicks (or visits) that converted — conversions divided by clicks
Deep Link
A link that opens an app straight to a specific screen instead of the home screen
Difference-in-Differences (DiD)
Subtract the control group's before/after change from the treated group's, removing shared factors
eCPI (Estimated CPI)
A modeled CPI estimate used when individual installs can't be observed, e.g. under SKAdNetwork
Frequency
Average number of times one person saw the same ad — impressions ÷ reach
Funnel
The step-by-step conversion path (impression → click → install → signup → purchase) that narrows at each stage
Holdout Test
Randomly withholding ads from part of an audience to measure true incrementality
Incremental ROAS (iROAS)
ROAS computed only on revenue the advertising actually added, after removing what would have happened anyway
Incrementality
The pure additional performance an ad actually caused
Learning Phase
The early period while the algorithm settles delivery — on Meta it ends at ~50 optimization events in 7 days
Lookalike Audience
Targeting where the platform finds people resembling a seed list you supply
LTV (Lifetime Value)
The total revenue a customer generates before they churn
Marginal CPA / Marginal ROAS
The CPA/ROAS of the next dollar added (or last dollar removed) at your current spend — the #1 metric for increasing, reallocating, or cutting budget
MMM (Marketing Mix Modeling)
Modelling channel spend against outcomes over time to estimate each channel's contribution
MMP (Mobile Measurement Partner)
A third-party service that aggregates conversion data from multiple ad networks into one attribution view
Multicollinearity
When independent variables move together so tightly a regression can't tell their effects apart
Payback Period
How long it takes a user's cumulative revenue to repay the cost of acquiring them
Postback
The server-to-server notification telling an ad network that an install or conversion happened
Probabilistic Attribution
Matching a click to an install by pattern (device, OS, timing) instead of a unique ID
Product Page Views
How many times the store product page was actually opened — the denominator of store conversion
Response Curve
The curve showing how conversions respond as spend increases — typically S-shaped
Retargeting
Serving ads again to users who already know or previously used the app
Retention
The share of installed/signed-up users still active after a given number of days
ROAS (Return On Ad Spend)
Revenue generated per dollar of ad spend — revenue divided by spend
SKAN (SKAdNetwork)
Apple's install attribution framework — anonymous, delayed, and aggregate-only
Statistical Power
The probability of detecting a real effect when one exists — a small sample misses effects that are there
Uplift
The outcome difference between treatment and control; interpreting it as incremental ad impact requires a valid design
View-Through Conversion
A conversion credited to an ad that was seen but never clicked