membership-growth-and-churn

name	membership-growth-and-churn
description	Read a fitness membership base as a subscription business: net member movement (joins minus churn), the retention/survival curve, member LTV = ARPU / churn, and the leaky-bucket diagnosis that tells you whether to fix acquisition or retention first. Churn/LTV benchmarks are verify-at-use.

Membership Growth & Churn

A gym is a subscription business. The number that matters is not gross joins but net movement and the retention curve — and the fastest way to lose money is to pour marketing into a leaky bucket.

The core identities

net member change   =  joins  -  churned members
member LTV (simple)  =  ARPU per month  /  monthly churn rate

A member at $150/month dues with 5% monthly churn is worth ~20 months × $150 = ~$3,000 in dues alone (before ancillary). Halve churn to 2.5% and LTV roughly doubles — which is why retention outperforms acquisition on unit economics. Treat the churn and ARPU inputs as [verify-at-use] against your own books.

The leaky-bucket diagnosis

Is the base growing?
  -> joins > churn  and churn near benchmark   ->  scale acquisition
  -> joins > churn  but churn high             ->  FIX churn first (marketing into a leaky bucket)
  -> joins < churn                             ->  retention emergency — stop spending on acquisition until the curve stabilizes

Metrics

Metric	What it tells you	Note
Monthly churn rate	Base durability	The denominator of LTV — move this first
Net member change	Real growth	Joins alone is a vanity number
Member LTV	What a member is worth	Drives allowable acquisition cost (CAC)
LTV : CAC ratio	Whether growth pays	Under target = acquisition is unprofitable
Retention/survival by cohort	Where members drop	Early-month cliff = onboarding problem

Anti-patterns

• Celebrating gross joins while net movement is flat or negative.
• Scaling ad spend on a base with above-benchmark churn.
• Quoting an LTV without dating the churn and ARPU inputs.

See also

• Traverse the churn-save triage and membership pricing / tier model trees in ../../knowledge/fitness-studio-decision-trees.md.
• Benchmarks (dated, verify-at-use): ../../knowledge/fitness-studio-reference-2026.md.
• Sibling skills: ../member-onboarding-and-retention/SKILL.md, ../ancillary-revenue-mix/SKILL.md.
• Best practices: ../../best-practices/retention-beats-acquisition-on-unit-economics.md, ../../best-practices/price-the-membership-on-value-and-commitment.md.