Welcome to the Tapp Glossary. This is your definitive guide to the acronyms and technical terms used in mobile app growth, referral marketing, and viral engineering. Use the index below to jump to a specific term.
Index
A | C | D | E | F | K | L | M | O | R | S | UA
App Links
Android App Links are the Google-specific implementation of deep links. They are standard web links (HTTPS) verified to belong to your app, allowing the OS to open content inside the app rather than a browser.
Learn More: Deep Links vs. Dynamic Links vs. Universal Links (2026 Guide)
API (Application Programming Interface)
A set of protocols that allows different software applications to communicate. At Tapp, our API allows you to programmatically generate referral links, trigger webhook payloads, and automate creator payouts via Stripe.
ASO (App Store Optimization)
The process of optimizing your App Store or Play Store listing to increase visibility. A well-executed referral loop often boosts your ASO by driving high-velocity traffic and conversion signals to the stores.
C
CAC (Customer Acquisition Cost)
The total cost spent to acquire a new paying user. Viral loops and first-party affiliate networks are the most effective way to lower blended CAC by generating organic, un-paid users.
CPA (Cost Per Action)
A payout model where you pay a creator or affiliate only when a referred user completes a high-intent event (e.g., subscribing to a Pro plan). This is the only way to guarantee a positive ROI on creator spend.
Learn More: CPI vs. CPA vs. RevShare: Choosing the Right Model
CPI (Cost Per Install)
A payout model based on app installs. Generally discouraged for high-growth subscription apps as it is highly susceptible to bot fraud and low-LTV traffic.
D
Deep Link
A URL that routes a user to a specific screen or piece of content inside an installed app. It bypasses the app’s home screen.
Learn More: Deep Links vs. Dynamic Links vs. Universal Links
Deferred Deep Linking
The industry-standard technology that makes mobile growth possible. If a user clicks a referral link but hasn’t installed your app, the link “defers” the destination. After the user installs the app, the Tapp SDK retrieves the original payload and routes them to the content they requested.
E
EPC (Earnings Per Click)
A metric used by affiliates to gauge the profitability of a program. It is the average commission an affiliate earns per 100 clicks. High-tier creators demand high EPC programs.
F
FDL (Firebase Dynamic Links)
A deprecated deep linking product from Google. FDL was officially shut down in 2025. If your codebase still references FDL, you are currently at risk of broken user journeys and loss of attribution data.
Learn More: How to Replace Firebase Dynamic Links with Tapp
K
K-Factor (Viral Coefficient)
The primary metric of virality. It represents the average number of new users brought in by each existing user. Formula: K = (Invitation Rate) * (Conversion Rate).
Learn More: The Engineer’s Guide to Building Viral Loops
KPI (Key Performance Indicator)
Measurable values used to track the health of a growth loop (e.g., K-Factor, Cycle Time, CAC, LTV).
L
LTV (Lifetime Value)
The predicted net profit attributed to the entire relationship with a customer. Your referral reward logic should always be based on LTV to ensure profitability.
M
MMP (Mobile Measurement Partner)
Third-party attribution platforms (like AppsFlyer or Adjust). Tapp can integrate with your existing tech stack to feed your MMP clean, attributed data.
O
OS (Operating System)
The foundational software layer (iOS/Android). Growth infrastructure must respect the strict privacy and sandboxing rules set by these OS providers.
R
RevShare (Revenue Share)
A payout model where creators receive a recurring percentage of the revenue generated by their referrals. This is the “gold standard” for retaining top-tier influencer talent.
ROI (Return on Investment)
The ultimate metric of growth. Referral programs should aim for a positive ROI by ensuring the acquisition cost (rewards paid out) is lower than the LTV of the acquired user.
S
SDK (Software Development Kit)
A toolkit for developers. The Tapp SDK is the lightweight piece of code you install to enable attribution, event tracking, and deep linking across your mobile app.
SEO (Search Engine Optimization)
The process of optimizing content to rank in search results. This glossary page serves as an E-E-A-T anchor for Tapp’s technical authority.
U
Universal Links
Apple’s native implementation for deep linking. It creates a secure, cryptographic relationship between your domain and your app to ensure seamless transitions.
UGC (User-Generated Content)
Content created by users (videos, graphics, reviews) that can be shared to drive organic growth. UGC loops are the most defensible forms of virality.
Learn More: Beyond Referrals: Social & UGC Viral Loops