Lean Analytics
Startup metrics and the One Metric That Matters
Choose and audit startup metrics using Alistair Croll and Benjamin Yoskovitz's Lean Analytics. This skill equips your AI agent with the discipline of the One Metric That Matters — separating actionable metrics from vanity numbers, matching metrics to your business model and stage, and drawing lines in the sand.
npx skills add wondelai/skills/lean-analytics --global 
Lean Analytics Alistair Croll & Benjamin Yoskovitz View on Amazon
02 What it is
What is the Lean Analytics skill?
Lean Analytics gives your agent the measurement half of the lean toolkit, from Croll and Yoskovitz’s book: choose the One Metric That Matters for your business model and stage, separate numbers that change a decision from ones that only look good in a board deck, and draw a line in the sand with a target, a date and a consequence.
03 Key concepts
Five principles your agent applies.
Drawn from Lean Analytics — not advice it repeats back to you, but decisions it makes while it works.
04 Fit
When to use it, and
when not to.
four symptoms it fixes, and four it doesn't.
Reach for it when
Your dashboard carries forty numbers and the weekly meeting is spent explaining which of them went up.
The headline metric is cumulative total signups, which by construction has never once gone down.
You are optimizing revenue while a third of new accounts never reach the core action a second time.
Someone asks whether four percent is a good conversion rate and nobody can say what good would look like here.
Reach for something else when
You need the experiment designed around the metric rather than the metric chosen. Lean Startup runs Build-Measure-Learn.
A checkout funnel is leaking and you want it diagnosed step by step. CRO Methodology is the sharper instrument.
Retention is the number and what you actually need is a behavioral intervention. Improve Retention designs that.
You are setting a price and need willingness-to-pay evidence, not a revenue metric. Monetizing Innovation covers it.
05 Prompts
Say it like this.
Name the skill at the end of a prompt and the agent applies the framework rather than a vibe. Or say nothing — it loads on its own when a task matches.
Pick the One Metric That Matters for our SaaS at our current stage using lean-analytics skill
Audit our dashboard for vanity metrics and rewrite them as ratios using lean-analytics skill
Build the metric tree for our marketplace with liquidity measures using lean-analytics skill
Set a line in the sand for churn with a pre-committed miss response using lean-analytics skill
06 About the author
07 Same stack
The stack it sits in.
Ten Product & Innovation skills. Most people run two: this one, and whichever fits the next problem.
All Product & Innovation skills08 Questions
Before you install.
How do I install the Lean Analytics skill?
Run npx skills add wondelai/skills/lean-analytics --global. It takes about 30 seconds and needs no account. The Lean Analytics skill then works in Claude, Claude Code, Claude Cowork, Codex, Cursor, OpenClaw and Hermes Agent — anything that reads the open agentskills.io format — and your agent loads it on its own when a task calls for it. It is free and MIT-licensed, and the source is at https://github.com/wondelai/skills.
Which book is the Lean Analytics skill based on?
It packages Lean Analytics by Alistair Croll & Benjamin Yoskovitz — serial founders, authors of the Lean Series data handbook. The skill distils the book's method into instructions your agent follows while it works, covering good vs vanity metrics, one metric that matters and metrics by business model. It sits in the Product & Innovation part of the library.
Does One Metric That Matters mean ignoring everything else?
No. It means one metric gets the team’s attention at a time, chosen because it measures the riskiest unproven part of the business right now — and it is expected to change as you move stages. Croll and Yoskovitz pair it with a counter-metric so it cannot be gamed: chase signups alone and you will buy junk traffic, pair signups with activation and you cannot. Everything else stays instrumented. It simply does not get to run the weekly meeting.
How is this different from the Lean Startup skill?
Ries gives you the loop; Croll and Yoskovitz give you the instrument panel. The Lean Startup tells you to measure what proves your leap-of-faith assumption and to prefer cohort behavior over cumulative totals — but not which numbers matter for a marketplace as opposed to a SaaS or a media site. Lean Analytics does: six business-model archetypes with their own metric trees, five stages with gates between them, and the classic mistake of optimizing a later stage’s metric before you have passed the earlier gate.
The benchmarks are from the early 2010s — is the book still useful?
Yes, with a caveat the skill will repeat back to you. Treat the specific numbers as shapes rather than targets; the structure has aged far better than the data — the four tests of a good metric, the stage gates, the per-model metric trees. Where you need genuine comparators, your own cohorts beat a decade-old industry median every time, and the skill will decline to hand you a published benchmark as though it were current.
Will it pull my actual numbers?
Only what you bring it, or what your agent can reach with the tools you have connected. The skill has no privileged access to your warehouse or product analytics. Where it earns its place is the argument before the query: which metric, which segment, which denominator, over what window, and what result would change the decision. A metrics framework applied to numbers nobody has instrumented yet is still just a plan — a much better plan, but a plan.
09 Guides that use it
Put it to work.
Long-form playbooks where this skill does part of the job.
One skill, one command.
Install Lean Analytics, or the whole stack.
npx skills add wondelai/skills/lean-analytics --global MIT licensed · Claude, Claude Code, Codex, Cursor, OpenClaw, Hermes · No account