/saas-economics-efficiency-metrics

name: saas-economics-efficiency-metrics
argument-hint: "[metrics or question]"
description: Evaluate SaaS unit economics and capital efficiency. Use when deciding whether the business can scale efficiently or needs correction.
intent: >-
  Determine whether your SaaS business model is fundamentally viable and capital-efficient. Use this to calculate unit economics, assess profitability, manage cash runway, and decide when to scale vs. optimize. Essential for fundraising, board reporting, and making smart investment trade-offs.
type: component
best_for:
  - "Checking whether a SaaS model is financially viable"
  - "Reviewing CAC, LTV, payback, burn, and Rule of 40 together"
  - "Preparing efficiency analysis for a board or leadership review"
scenarios:
  - "Evaluate our SaaS unit economics before we scale paid acquisition"
  - "Help me analyze CAC payback, LTV, and burn for our product"
  - "I need a SaaS efficiency check for our board deck"
theme: finance-metrics
estimated_time: "10-15 min"

Purpose

Determine whether your SaaS business model is fundamentally viable and capital-efficient. Use this to calculate unit economics, assess profitability, manage cash runway, and decide when to scale vs. optimize. Essential for fundraising, board reporting, and making smart investment trade-offs.

This is not a finance reporting tool—it's a framework for PMs to understand whether the business can sustain growth, when to prioritize efficiency over growth, and which investments have positive returns.

Input

**Works best with:** The question you're answering (can we scale? raise? extend runway?) or the metrics you want evaluated. **Also useful:** Your numbers — CAC, gross margin, burn, runway, magic number — partial data is workable.

Anything supplied with the invocation itself — text after the skill name, a pasted context dump, or an appended `ARGUMENTS:` line — counts as answers already given. Use it and skip whatever it covers; don't re-ask.

**Arriving empty-handed? That works too.** Use it as a reference: read the metric sections relevant to your stage and decision.

**Example invocation:** `Are we efficient enough to scale? CAC $9K, gross margin 72%, burn multiple 2.1, magic number 0.6.`

Key Concepts

Unit Economics Family

Metrics that measure profitability at the customer level—the foundation of sustainable SaaS.

**Gross Margin** — Percentage of revenue remaining after direct costs (COGS).

• **Why PMs care:** A feature that generates $1M revenue at 80% margin is worth far more than $1M at 30% margin. Margin determines which features to prioritize.
• **Formula:** `(Revenue - COGS) / Revenue × 100`
• **COGS includes:** Hosting, infrastructure, payment processing, customer onboarding costs
• **Benchmark:** SaaS 70-85% good; <60% concerning

**CAC (Customer Acquisition Cost)** — Total cost to acquire one customer.

• **Why PMs care:** Shapes entire go-to-market strategy. Determines which channels are viable and how much you can invest in product-led growth.
• **Formula:** `Total Sales & Marketing Spend / New Customers Acquired`
• **Benchmark:** Varies by model—Enterprise $10K+ ok; SMB <$500 target
• **Include:** Marketing spend, sales salaries, tools, commissions

**LTV (Lifetime Value)** — Total revenue expected from one customer over their lifetime.

• **Why PMs care:** Tells you what you can afford to spend on acquisition. Higher LTV enables premium channels and longer payback periods.
• **Formula (simple):** `ARPU × Average Customer Lifetime (months)`
• **Formula (better):** `ARPU × Gross Margin % / Churn Rate`
• **Formula (advanced):** Account for expansion, discount rates, cohort-specific retention
• **Benchmark:** Must be 3x+ CAC; varies by segment

**LTV:CAC Ratio** — Efficiency of customer acquisition spending.

• **Why PMs care:** Is growth sustainable or are you buying revenue at a loss? Determines when to scale vs. optimize.
• **Formula:** `LTV / CAC`
• **Benchmark:** 3:1 healthy; <1:1 unsustainable; >5:1 might be underinvesting
• **Note:** This ratio alone doesn't tell the full story—also need payback period

**Payback Period** — Months to recover CAC from customer revenue.

• **Why PMs care:** Cash efficiency. Faster payback = reinvest sooner. Slow payback can kill growth even with good LTV:CAC.
• **Formula:** `CAC / (Monthly ARPU × Gross Margin %)`
• **Benchmark:** <12 months great; 12-18 ok; >24 months concerning
• **Critical:** Must have cash to sustain payback period

**Contribution Margin** — Revenue remaining after ALL variable costs (not just COGS).

• **Why PMs care:** True unit profitability. Includes support, processing fees, variable OpEx.
• **Formula:** `(Revenue - All Variable Costs) / Revenue × 100`
• **Variable costs:** COGS + support + payment processing + variable customer success
• **Benchmark:** 60-80% good for SaaS; <40% concerning

**Gross Margin Payback** — Payback period using actual profit, not revenue.

• **Why PMs care:** More accurate than simple payback. Shows true cash recovery time.
• **Formula:** `CAC / (Monthly ARPU × Gross Margin %)`
• **Benchmark:** Typically 1.5-2x longer than simple revenue payback

**CAC Payback by Channel** — Compare payback across acquisition channels.

• **Why PMs care:** Not all channels are created equal. Optimize channel mix based on payback efficiency.
• **Formula:** Calculate CAC and payback separately for each channel
• **Use:** Allocate budget to faster-payback channels when cash-constrained

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Capital Efficiency Family

Metrics that measure how efficiently you use cash to grow the business.

**Burn Rate** — Cash consumed per month.

• **Why PMs care:** Determines what you can build and when you need funding. High burn requires aggressive revenue growth.
• **Formula (Gross Burn):** `Monthly Cash Spent (all expenses)`
• **Formula (Net Burn):** `Monthly Cash Spent - Monthly Revenue`
• **Benchmark:** Net burn <$200K manageable for early stage; >$500K needs clear path to revenue

**Runway** — Month