SaaS Glossary — Plain-English Definitions
72 plain-English definitions covering SaaS metrics, AI concepts, proxy types, web scraping, and affiliate marketing — written for practitioners, not textbooks.
72 of 72 terms
A
AI Agent
An AI agent is an LLM that autonomously takes multi-step actions using tools. Learn how agent loops work, why errors compound, and what's needed for safe production deployment.
API-First
API-first means every product feature is accessible via API. Learn why API-first is a growth strategy, what moats it creates, and examples from Stripe, Twilio, and Cloudflare.
ARPU (Average Revenue Per User)
ARPU is total recurring revenue divided by paying accounts. Learn how to calculate ARPU, what rising vs. falling ARPU signals, and how it feeds into LTV.
ARR (Annual Recurring Revenue)
What ARR is, how it differs from booked revenue, and why boards use it as the headline SaaS metric.
Affiliate Network
What an affiliate network is, how they make money, and the major SaaS and consumer networks operating in 2026.
Anti-Bot Detection
Anti-bot detection uses behavioral analysis, fingerprinting, and ML to block automated requests. Learn how modern systems like Cloudflare Bot Management work and how scrapers counter them.
Attribution Window
What an attribution window is, typical durations by vertical, and why it drives affiliate economics.
B
C
CAC (Customer Acquisition Cost)
CAC is the total cost to acquire one new paying customer. Learn how it's calculated, why the CAC:LTV ratio matters, and how SaaS teams use it to evaluate growth efficiency.
CAC Payback Period
CAC payback period is how many months to recover customer acquisition cost via gross profit. Learn the formula and what payback periods indicate at different SaaS stages.
CAPTCHA
CAPTCHAs are automated bot-detection challenges that block scrapers. Learn how different CAPTCHA types work and how scraping pipelines solve or bypass them.
CPA (Cost Per Action)
CPA is an affiliate model that pays only for completed conversions — purchases, signups, or leads. Learn CPA rates, how it aligns affiliate incentives, and which networks use it.
CPC (Cost Per Click)
CPC charges advertisers per click, regardless of conversion. Learn how CPC compares to CPA in affiliate marketing, and why SaaS niches command high per-click rates.
CPM (Cost Per Mille)
CPM charges advertisers per 1,000 impressions. Learn how CPM fits into affiliate and display advertising, how to benchmark it, and what B2B SaaS newsletter CPMs look like.
CSS Selector
CSS selectors identify HTML elements for data extraction in web scraping. Learn how to write robust selectors using data attributes and semantic roles to reduce maintenance.
Churn
Definition of churn, gross vs net churn, and SaaS benchmarks by segment.
Concurrent Connections
Concurrent connections is how many simultaneous proxy requests a plan supports. Learn how concurrency affects scraping throughput and why it's a key proxy pricing differentiator.
Context Window
The context window is the maximum text an LLM can process per request, measured in tokens. Learn how context window size affects RAG pipelines, latency, and cost.
Contraction MRR
Contraction MRR is recurring revenue lost when customers downgrade without cancelling. Learn why it's an early churn warning signal and how to reduce it.
Cookie Duration
Affiliate cookie duration is how long tracking cookies stay active after a click. Learn how cookie length affects which affiliates get credited and why server-side tracking is replacing it.
D
DOM (Document Object Model)
The DOM is the live in-memory tree browsers build from HTML and JavaScript. Learn why scrapers need DOM access for modern SPAs and when raw HTML is enough.
Datacenter Proxy
What a datacenter proxy is, where it outperforms residential, and typical per-GB pricing ranges.
Deep Linking (Affiliate)
Affiliate deep linking sends users directly to a specific landing page rather than the homepage. Learn how deep links boost conversion rates and which networks support them.
E
EPC (Earnings Per Click)
EPC measures affiliate revenue per 100 clicks. Learn how to calculate EPC, use it to compare offers, and set maximum CPC bids for traffic buying.
Embeddings
Embeddings are vector representations of text that capture semantic meaning for AI search and retrieval. Learn how embeddings work and why they power RAG, recommendations, and semantic search.
Exit Node
The exit node is the final device in a proxy chain whose IP the target website sees. Learn how exit nodes work in residential networks and why their quality affects scraping performance.
Expansion MRR
Expansion MRR is the additional recurring revenue earned from existing customers through upgrades and upsells. Learn why it's often the cheapest revenue to grow.
F
Fine-Tuning
Fine-tuning adapts a pre-trained AI model on a smaller domain-specific dataset. Learn when fine-tuning makes sense vs. RAG, and what it costs to specialize an LLM.
Foundation Model
A foundation model is a large AI model trained broadly and adapted for many tasks. Learn how foundation models like Claude, GPT-4, and Llama underpin the modern AI stack.
Freemium
Freemium is a pricing model with a permanently free tier and paid upgrades. Learn how freemium gates work, typical conversion rates, and when freemium makes sense for SaaS.
G
GRR (Gross Revenue Retention)
GRR measures recurring revenue kept from existing customers, excluding expansion. Learn how GRR differs from NRR and why both matter for SaaS health.
Generative AI
Generative AI produces new content — text, images, code, audio — rather than classifying existing data. Learn how it differs from traditional AI and why it changes product design.
Geo-Targeting (Proxy)
Proxy geo-targeting selects IPs from specific countries, regions, or cities. Learn why geo-targeting matters for price monitoring, SERP data, and ad verification.
H
I
ICP (Ideal Customer Profile)
ICP is a data-driven profile of the company most likely to buy and retain your SaaS product. Learn how it differs from a buyer persona and how a precise ICP improves every growth metric.
IP Rotation
IP rotation cycles through proxy IP addresses to avoid detection and rate limiting. Learn rotation strategies, when to use sticky sessions, and how pool size affects success rates.
IP Whitelisting
IP whitelisting restricts access to pre-approved IP addresses. Learn how proxy providers support whitelisting, when static IPs are needed, and how it fits into security compliance.
ISP Proxy
ISP proxies combine datacenter speed with residential IP legitimacy. Learn how they differ from datacenter and rotating residential proxies, and when to use each.
Inference (AI)
AI inference is running a trained model on new input to generate output. Learn how inference differs from training, why latency and cost matter, and how teams optimize it.
J
L
LLM (Large Language Model)
An LLM is a deep learning model trained on text to generate human language. Learn how LLMs like GPT-4 and Claude work, what shapes their capabilities, and their core limitations.
LTV (Customer Lifetime Value)
LTV is the total revenue a customer generates over their lifetime. Learn the LTV formula, how it interacts with CAC, and why LTV:CAC ratio is the core SaaS unit-economics check.
M
MRR (Monthly Recurring Revenue)
Plain-English definition of MRR, how it is calculated, and why it drives SaaS valuation.
Mobile Proxy
Mobile proxies route traffic through real carrier-connected devices, making them the hardest to block. Learn why mobile IPs command premium prices and when they're worth it.
Multi-Tenancy
Multi-tenancy is a SaaS architecture where one software instance serves many customers with isolated data. Learn how it differs from single-tenancy and why it matters for SaaS economics.
N
P
PLG (Product-Led Growth)
PLG is a strategy where the product drives acquisition and expansion, not sales or marketing. Learn how freemium, free trials, and self-serve onboarding power product-led companies.
Postback URL (S2S Tracking)
Postback URLs enable server-to-server affiliate conversion tracking without cookies or pixels. Learn why S2S tracking is more reliable and how networks implement it.
Prompt Engineering
Prompt engineering is crafting LLM inputs to reliably produce desired outputs. Learn techniques like chain-of-thought, few-shot prompting, and system prompt design.
Proxy Pool
A proxy pool is the full inventory of IPs a proxy provider maintains for rotation. Learn why pool quality matters more than size and how freshness and diversity affect scraping success.
Publisher & Advertiser
Publishers earn affiliate commissions by driving traffic; advertisers pay for conversions. Learn how the publisher-advertiser-network structure works and what each party controls.
R
RAG (Retrieval-Augmented Generation)
Plain-English definition of RAG, when you need it, and the common failure modes.
RLHF (Reinforcement Learning from Human Feedback)
RLHF is the training technique that aligns LLMs to human preferences using rated examples. Learn how RLHF shapes chatbot behavior and why rating guideline quality matters.
Rate Limiting
Rate limiting caps how many requests an IP or API key can make in a time window. Learn how scrapers handle 429 errors, back-off strategies, and per-domain throttling.
Residential Proxy
Plain-English definition of residential proxies, when you need them, and how to evaluate providers.
Revenue Share (RevShare)
RevShare pays affiliates an ongoing percentage of each referred customer's payments. Learn how revenue share aligns affiliate incentives with retention and typical SaaS RevShare rates.
Rotating Proxy
A rotating proxy cycles through IP addresses per request to avoid blocks. Learn how rotating proxies work, when to use rotation vs. sticky sessions, and what pool quality means.
Rule of 40
The Rule of 40 states that a SaaS company's growth rate plus profit margin should exceed 40%. Learn why it's the go-to investor benchmark for growth-efficiency balance.
S
SOCKS5 Proxy
SOCKS5 is a network-layer proxy protocol that routes any TCP/UDP traffic. Learn how it differs from HTTP proxies, supports authentication, and what use cases it unlocks.
Seat-Based Pricing
Seat-based pricing charges a flat fee per user or license. Learn how per-seat models work, their expansion ceiling problem, and how SaaS companies layer additional pricing on top.
Sticky Session
What a sticky session is, why it matters for logged-in scraping, and how to configure it.
Sub-Affiliate
A sub-affiliate is recruited by a master affiliate who earns override commissions. Learn how two-tier affiliate structures work and why networks use them to attract super-affiliates.
T
Token (AI)
An AI token is the basic unit of text an LLM processes — roughly ¾ of a word. Learn how tokens affect context windows, API pricing, and how to optimize token usage.
Tracking Pixel
A tracking pixel fires a server request to record ad impressions or conversions. Learn why pixels are being replaced by server-side postbacks and Conversion APIs in modern affiliate programs.
U
Usage-Based Pricing (UBP)
Usage-based pricing charges for what you consume — API calls, data, or seats. Learn how UBP aligns vendor and customer growth and why Stripe and Twilio use it.
User Agent
The user agent identifies client software in HTTP requests. Learn how scrapers spoof user agents, why header order matters, and how browser fingerprinting goes beyond UA strings.
V
W
Web Crawling
Web crawling automatically traverses websites by following links to discover content. Learn how crawling differs from scraping and how it works in search engines and data pipelines.
Web Scraping
Web scraping is automated data extraction from websites. Learn how scrapers work, the technical challenges of modern anti-bot systems, and the legal considerations.
White-Labeling
White-labeling lets partners rebrand a SaaS product as their own. Learn how white-label deals work, who benefits, and the trade-offs for SaaS vendors.