Glossary

SaaS & churn glossary

Key terms and metrics every SaaS founder should know. From churn rate to dunning, here's what the jargon actually means.

C

Definition

Churn Rate

The percentage of customers or subscribers who cancel or stop paying during a given time period.

Definition

Committed MRR (CMRR)

A forward-looking MRR metric that accounts for known upcoming changes like signed contracts, confirmed cancellations, and pending upgrades.

Definition

Contraction MRR

The monthly recurring revenue lost when existing customers downgrade to a lower plan or reduce their usage.

Definition

Customer Attrition

The gradual loss of customers over time, whether through cancellation, non-renewal, or failed payments.

Definition

Customer Effort Score (CES)

A survey-based metric that measures how much effort a customer had to expend to complete a specific interaction with your product or support team.

Definition

Customer Engagement Score

A metric that quantifies how actively a customer interacts with your product, based on usage frequency, feature breadth, and depth of activity.

Definition

Customer Health Score

A composite metric that combines usage, engagement, and satisfaction signals to predict how likely a customer is to renew or churn.

Definition

Customer Lifetime Value (LTV)

The total revenue a single customer is expected to generate over the entire duration of their subscription.

Definition

Customer Segmentation

The practice of grouping customers by shared characteristics to analyse behaviour, retention, and revenue patterns at a granular level.

Definition

Customer Success Metrics

The metrics used by customer success teams to measure customer satisfaction, engagement, health, and likelihood of retention.

S

Definition

SaaS KPIs

The key performance indicators used to measure growth, retention, revenue health, and operational efficiency of a SaaS business.

Definition

SaaS Magic Number

A sales efficiency metric that measures how much net new ARR each dollar of sales and marketing spend generates.

Definition

SaaS Quick Ratio

A growth efficiency metric that compares revenue gains (new + expansion MRR) against revenue losses (churned + contraction MRR).

Definition

SaaS Unit Economics

The per-customer financial metrics that determine whether a SaaS business can profitably acquire, retain, and grow its customer base.

Definition

Soft Decline

A temporary payment failure where the card is valid but the transaction was rejected for a transient reason, and can be retried.

Definition

Subscriber Churn

The rate at which subscribers cancel or lapse from a subscription service, whether by choice or due to payment failure.

Definition

Subscription Churn Rate

The percentage of active subscriptions that end during a given period, typically measured monthly.

Definition

Subscription KPIs

The key performance indicators used to measure the financial health, growth, and retention of a subscription business.

Definition

Subscription Metrics

The financial and operational metrics used to measure the health and growth of a subscription-based business model.

Definition

Subscription Revenue

The recurring income a business earns from customers who pay on a regular billing cycle for ongoing access to a product or service.