Board reporting includes LTV:CAC, payback period, NRR, and burn multiple as headline metrics.

LTV ≥ 3× CAC, recover CAC in <12 months — and expect a multi-year cash flow trough before it pays off

Q: Mechanism

SaaS economics are cash-intensive because customers pay monthly while CAC is incurred upfront. Each new customer creates a temporary cash deficit; faster growth means deeper trough but steeper eventual profitability curve. The unit economics decompose into three levers: acquire efficiently (CAC, payback period), retain (churn, NRR > 100% = "negative churn"), monetize over time (expansion revenue from existing customers). LTV:CAC < 3 is a diagnostic that something is broken in product, sales, or fit — not just finance.

Q: Evidence

> "LTV should be at least 3x CAC (the 'golden ratio' that became an industry standard), and CAC should be recovered in under 12 months."

Q: Counter-evidence

Some categories (consumer SaaS with viral acquisition, infrastructure with land-and-expand) operate on different unit-economics shapes where the 3:1 ratio is too conservative or too lenient. Burn-multiple advocates (David Sacks, Bessemer) argue burn ratio is a more honest single-number metric for the post-2022 SaaS environment.

Claim

A SaaS business is viable only if the lifetime value of a customer significantly exceeds the cost to acquire them. Skok's golden ratios: LTV:CAC ≥ 3, months-to-recover-CAC < 12. Halving churn doubles LTV — making retention the highest-leverage lever. Hiring sales reps and acquiring customers creates a cash flow trough (deeper the faster you grow), with first profit often only 18-21 months in.

Mechanism

SaaS economics are cash-intensive because customers pay monthly while CAC is incurred upfront. Each new customer creates a temporary cash deficit; faster growth means deeper trough but steeper eventual profitability curve. The unit economics decompose into three levers: acquire efficiently (CAC, payback period), retain (churn, NRR > 100% = "negative churn"), monetize over time (expansion revenue from existing customers). LTV:CAC < 3 is a diagnostic that something is broken in product, sales, or fit — not just finance.

Conditions

Holds when:

The business is true subscription SaaS with measurable churn and customer cohorts.
The team has clean data on fully-loaded CAC (not just media spend).

Fails when:

Pre-PMF startups where churn and LTV are too noisy to trust.
Usage-based or hybrid revenue models where LTV calculation needs different formulas.

Evidence

"LTV should be at least 3x CAC (the 'golden ratio' that became an industry standard), and CAC should be recovered in under 12 months."

"Halving the churn rate doubles LTV, making churn reduction far more impactful than acquisition optimization."

"When a company hires two new salespeople per month to drive growth, his model shows a worst monthly loss of $190K and first profit only after 21 months."

— David Skok, SaaS Metrics 2.0 (synthesized from operator's published work)

Signals

Board reporting includes LTV:CAC, payback period, NRR, and burn multiple as headline metrics.
Sales-rep-level unit economics are modeled (ramp time, expected payback per hire, expected fail rate ~30-40%).
Hiring velocity decisions reference the cash-flow-trough model, not just runway.

Counter-evidence

Some categories (consumer SaaS with viral acquisition, infrastructure with land-and-expand) operate on different unit-economics shapes where the 3:1 ratio is too conservative or too lenient. Burn-multiple advocates (David Sacks, Bessemer) argue burn ratio is a more honest single-number metric for the post-2022 SaaS environment.

Cross-references

(none in current corpus)