# Metrics
There's an art to picking the right metric. Get it right and you create clarity across an organisation. Each one says: this is what matters, measure it this way, here's what good looks like.
The point is insight — seeing something you couldn't see before.
EBITDA exists because John Malone needed to value cable companies with massive depreciation and interest costs — earnings made no sense for his business. LTV:CAC came from SaaS investors comparing subscription economics. Rule of 40 from the trade-off between growth and profitability.
At the extreme, the metric becomes the strategy. See [[Serial Acquirers/The Bergman & Beving Legacy|Bergman & Beving]] and [[Serial Acquirers/The Roper Model|Roper]].
Focus means omission. Every metric has gaps and weaknesses worth understanding. What follows explores the concepts I've found most useful to understand deeply.
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## Foundations
*The conceptual building blocks.*
- **[[Notes/Ratios|Ratios]]** — Dividing one number by another is the simplest analytical move. It is also one of the most powerful.
- **[[Notes/Scale|Scale]]** — Before asking if a number is exactly right, ask if it is roughly right. Most errors are 10x, not 10%.
- **[[Notes/Confidence|Confidence]]** — A number without a confidence level is a guess dressed as a fact.
- **[[Notes/Variance|Variance]]** — Not all variation requires action. Knowing when to react and when to wait is half of operational judgement.
- **[[Notes/Small Samples|Small Samples]]** — At n=20, the qualitative signal is more reliable than the quantitative noise.
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## Evaluating a subscription business
*How sticky is the revenue? Where is the ceiling?*
- **[[Notes/Recurring Revenue|Recurring Revenue]]** — Recurring revenue determines how hard you have to run just to stand still.
- **[[Notes/Gross vs Net Retention|Gross vs Net Retention]]** — Gross retention measures churn. Net retention measures growth from existing customers.
- **[[Notes/Non-Renewal vs Churn|Non-Renewal vs Churn]]** — Customer decisions vs revenue outcomes. Different denominators, different insights.
- **[[Notes/Retention Decay|Retention Decay]]** — Why 95% retention is fundamentally different from 90%.
- **[[Notes/The 95% Illusion|The 95% Illusion]]** — Contract length and measurement period distort reported retention.
- **[[Notes/Limits to Growth|Limits to Growth]]** — Every recurring revenue business has a ceiling. The maths is unforgiving.
- **[[Notes/Rule of 40|Rule of 40]]** — Growth and profitability usually trade off. Are you managing it well?
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## Understanding unit economics
*Does adding customers create value or consume it?*
- **[[Notes/Unit Economics|Unit Economics]]** — How to diagnose whether growth creates value or consumes capital.
- **[[Notes/Payback Period|Payback Period]]** — When customer acquisition becomes self-funding.
- **[[Notes/Payback Over Ratios|Payback Over Ratios]]** — CAC payback period matters more than LTV:CAC.
- **[[Notes/Contribution Margin vs Gross Margin|Contribution Margin vs Gross Margin]]** — Two margins, two questions. Product vs customer.
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## Assessing capital efficiency
*How hard is the capital working? Where does the cash go?*
- **[[Notes/Asset Turnover|Asset Turnover]]** — Margin gets all the attention. Turnover is where the real leverage hides.
- **[[Notes/Margins vs Growth|Margins vs Growth]]** — Once returns are high enough, the bigger lever is finding reinvestment opportunities.
- **[[Notes/Cash Return on Investment|Cash Return on Investment]]** — CRI measures what you get back, in cash, relative to what you put in.
- **[[Notes/EBITA-WC|EBITA-WC]]** — The ratio serial acquirers use to focus managers on controllable levers.
- **[[Notes/FCF Conversion|FCF Conversion]]** — Profits are accounting. Cash is real. The gap reveals business quality.
- **[[Notes/Customer-Funded Growth|Customer-Funded Growth]]** — Some businesses need capital to grow. Others generate cash by growing.
- **[[Notes/Profitable and Broke|Profitable and Broke]]** — Why profitable companies run out of cash. Working capital constrains growth.
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## Measuring operational performance
*Is the machine getting better or worse?*
- **[[Notes/Revenue per FTE|Revenue per FTE]]** — The productivity metric that reveals operating leverage.
- **[[Notes/Organic vs Acquired Growth|Organic vs Acquired Growth]]** — The distinction that shows whether a company can grow without buying growth.
- **[[Notes/ROI and the Cost of Delay|ROI and the Cost of Delay]]** — Time erodes ROI. Delay compounds. Speed is a margin decision.
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## Reading software financials
*What the headline numbers hide.*
- **[[Notes/EBITDA in Software|EBITDA in Software]]** — How software gets priced. Where the gaps between accounting and cash hide.
- **[[Notes/Accounting for Widgets|Accounting for Widgets]]** — Why inherited numbers mislead. Throughput over cost accounting.
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