Growth analytics
Guide founders through metrics frameworks, experimentation, and data-driven growth. Use when a founder says "help me set up my metrics framework", "what should my north star metric be?", "design an A/B test", "help me analyze retention/churn", "build me a dashboard to track growth", "how do I do cohort analysis?", "what metrics should I track?", "pirate metrics", "AARRR funnel", or needs to make sense of their growth data.From its SKILL.md
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SKILL.md
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Growth & Analytics
Guide founders from defining their first metrics (pre-launch) through sophisticated retention analysis and experimentation (post-launch).
Workflow
1. Diagnose Current State
Ask: "Where are you in your analytics journey?"
| State | Signals | Next Step |
|---|---|---|
| Pre-launch | No users yet, needs to define what to track | → Step 2: Metrics Framework |
| Early traction | Has users, unclear what metrics matter | → Step 2: Metrics Framework |
| Tracking basics | Has metrics, needs North Star focus | → Step 2: North Star Selection |
| Ready to experiment | Solid metrics, wants to run tests | → Step 3: A/B Testing |
| Retention concerns | Users churning, needs analysis | → Step 4: Retention & Cohorts |
| Dashboard needed | Wants visibility for team/investors | → Step 5: Dashboard Design |
2. Metrics Framework
Build a metrics system that drives the right behavior. See references/metrics-frameworks.md for complete framework library.
AARRR Pirate Metrics
The universal startup funnel framework:
| Stage | Question | Example Metrics |
|---|---|---|
| Acquisition | How do users find you? | Visitors, signups, CAC by channel |
| Activation | Do they have a great first experience? | Completed onboarding, "aha moment" reached |
| Retention | Do they come back? | DAU/MAU, D1/D7/D30 retention, churn |
| Revenue | Do they pay? | Conversion rate, ARPU, LTV |
| Referral | Do they tell others? | NPS, referral rate, viral coefficient |
Stage-Appropriate Focus:
| Stage | Primary Focus | Why |
|---|---|---|
| Pre-PMF | Activation + Retention | Nothing else matters if product doesn't stick |
| Post-PMF | Revenue + Acquisition | Time to scale what works |
| Growth | All five, plus efficiency | Optimize the full funnel |
North Star Metric
One metric that best captures core value delivered to customers.
Selection Criteria:
- Measures value — Correlates with customers getting value
- Leading indicator — Predicts future revenue/growth
- Actionable — Team can influence it
- Simple — Easy to understand and communicate
North Star Examples by Business Model:
| Model | North Star | Why |
|---|---|---|
| B2B SaaS | Weekly Active Users, Features Used | Value = engagement with product |
| Marketplace | Transactions completed | Both sides getting value |
| Subscription | Weekly active subscribers | Retention predicts LTV |
| E-commerce | Repeat purchase rate | Loyalty = sustainable revenue |
| Usage-based | Monthly usage volume | Usage = revenue |
| Social/Consumer | DAU/MAU ratio | Engagement intensity |
Supporting Metrics:
Every North Star needs 3-5 supporting metrics that explain HOW to move it:
North Star: Weekly Active Teams (B2B SaaS)
├── Activation: Teams completing onboarding
├── Engagement: Features used per team
├── Expansion: Seats added per team
└── Retention: Team churn rate
One Metric That Matters (OMTM)
For early-stage focus, pick ONE metric for a defined period:
OMTM Selection:
- What's the biggest constraint right now?
- What metric would prove that constraint is solved?
- Can you move it in 4-8 weeks?
Examples:
- Pre-launch: "Waitlist signups" (validate demand)
- Beta: "D7 retention" (validate stickiness)
- Post-launch: "Activation rate" (validate onboarding)
- Growth: "Payback period" (validate unit economics)
3. A/B Testing & Experimentation
Run experiments that generate reliable insights. See references/ab-testing.md for templates and calculators.
Experiment Design Framework
Hypothesis Structure:
If we [change], then [metric] will [improve/decrease] by [amount]
because [reason based on user insight].
Example:
If we reduce signup form from 5 fields to 3 fields, then signup completion rate will increase by 15% because user research shows form length is the #1 drop-off reason.
Before Running Any Test
Pre-flight Checklist:
| Check | Question | Action |
|---|---|---|
| Sample size | Do we have enough traffic? | Calculate minimum sample (see below) |
| Duration | How long to reach significance? | Usually 1-4 weeks minimum |
| Metric clarity | What exactly are we measuring? | Define primary + guardrail metrics |
| Segment impact | Should we segment results? | Pre-define segments (new vs returning, mobile vs desktop) |
Sample Size Estimation:
For 80% power and 95% confidence:
- 10% baseline, detect 10% relative lift → ~15,000 per variant
- 10% baseline, detect 20% relative lift → ~4,000 per variant
- 2% baseline, detect 20% relative lift → ~20,000 per variant
Rule of thumb: Multiply expected traffic by test duration. If you can't reach minimum sample in 4 weeks, the test isn't worth running—make a bigger change.
Running the Test
Test Execution Rules:
- Run for full weeks (capture day-of-week effects)
- Don't peek early—commit to duration
- Track guardrail metrics (what shouldn't break)
- Document everything before launch
Guardrail Metrics Examples:
- Revenue per user (main metric might improve but hurt revenue)
- Page load time (change might slow performance)
- Support tickets (change might confuse users)
Interpreting Results
| Result | Interpretation | Action |
|---|---|---|
| Significant win | p < 0.05, metric improved | Ship it, document learnings |
| Significant loss | p < 0.05, metric declined | Don't ship, learn why |
| Inconclusive | p > 0.05 | Not enough data OR no real effect |
| Flat | Large sample, no movement | Effect likely too small to matter |
Common Pitfalls:
- Stopping early when results look good (inflates false positives)
- Testing too many variants (dilutes sample)
- Ignoring segments (average hides important differences)
- No hypothesis (test without learning)
4. Retention & Cohort Analysis
Understand if users stick around. See references/retention-cohorts.md for SQL templates and benchmarks.
Retention Fundamentals
Types of Retention:
| Type | Definition | Use When |
|---|---|---|
| N-day retention | % of users active on exactly day N | Daily-use products (social, games) |
| Bounded retention | % active within day range (e.g., week 1) | Weekly-use products (SaaS) |
| Unbounded retention | % active on day N or any day after | Long purchase cycles (e-commerce) |
Critical Retention Points:
| Timeframe | What It Measures | Healthy Benchmark |
|---|---|---|
| D1 | First impression | >25% (consumer), >40% (B2B) |
| D7 | Habit forming | >15% (consumer), >30% (B2B) |
| D30 | Stickiness | >10% (consumer), >25% (B2B) |
| D90 | Long-term value | Product-dependent |
Cohort Analysis
Group users by signup date (or other dimension) to track behavior over time.
Cohort Table Structure:
| Cohort | Week 0 | Week 1 | Week 2 | Week 3 | Week 4 |
|---|---|---|---|---|---|
| Jan 1-7 | 100% | 40% | 30% | 25% | 22% |
| Jan 8-14 | 100% | 45% | 35% | 28% | 25% |
| Jan 15-21 | 100% | 48% | 38% | 32% | — |
Reading Cohort Tables:
- Rows = Compare cohorts (are newer users retaining better?)
- Columns = Retention decay (where's the biggest drop-off?)
- Diagonals = Same calendar week (external events)
Cohort Dimensions Beyond Time:
- Acquisition channel (organic vs. paid)
- Plan type (free vs. paid)
- First action taken (feature X vs. feature Y)
- Geography
Retention Curves
Healthy Curve Shape:
100% ─┐
│╲
│ ╲
│ ╲____________________ ← Flattens = retention
│
0% ─┴─────────────────────────
D1 D7 D30 D60 D90
Danger Signs:
- Curve never flattens (continuous bleed)
- Steep drop after D1 (activation problem)
- Drop at specific point (feature/billing issue)
Churn Analysis
Churn Rate Calculation:
Monthly Churn = Customers Lost This Month / Customers at Start of Month
Churn Benchmarks (SaaS):
| Segment | Good | Great |
|---|---|---|
| SMB | <5% monthly | <3% monthly |
| Mid-market | <2% monthly | <1% monthly |
| Enterprise | <1% monthly | <0.5% monthly |
Churn Diagnosis Questions:
- When do they churn? (Tenure analysis)
- Who churns? (Segment analysis)
- Why do they churn? (Exit surveys, support tickets)
- What predicts churn? (Behavioral signals)
5. Dashboard Design
Create visibility that drives action. See references/dashboard-design.md for templates and tool recommendations.
Dashboard Hierarchy
Level 1: Executive Dashboard (weekly, whole company)
- 3-5 top-level KPIs
- Trend vs. target
- One screen, no scrolling
Level 2: Functional Dashboards (daily, by team)
- Sales: Pipeline, conversion, activity
- Product: Engagement, retention, feature adoption
- Marketing: Acquisition, CAC, channel performance
- Support: Tickets, response time, CSAT
Level 3: Operational Dashboards (real-time, by function)
- Engineering: Uptime, latency, errors
- Sales: Daily activity, quota attainment
KPI Selection
For Each Metric, Answer:
- What decision does this inform?
- Who needs to see it and how often?
- What's the target and why?
- What action triggers if it's off-track?
Metric Types to Include:
| Type | Purpose | Example |
|---|---|---|
| Leading | Predict future outcomes | Pipeline, activation rate |
| Lagging | Confirm results | Revenue, churn |
| Input | Activities you control | Calls made, features shipped |
| Output | Outcomes you want | Deals closed, retention |
Visualization Principles
Choosing Chart Types:
| Data Type | Best Chart |
|---|---|
| Trend over time | Line chart |
| Comparison across categories | Bar chart |
| Part-to-whole | Pie (if <5 segments), stacked bar |
| Distribution | Histogram |
| Correlation | Scatter plot |
| Funnel stages | Funnel chart |
Dashboard Anti-Patterns:
- ❌ Too many metrics (more than 8-10 per view)
- ❌ No context (numbers without targets/trends)
- ❌ Vanity metrics (impressive but not actionable)
- ❌ Stale data (updated monthly when weekly needed)
- ❌ No owner (who acts on this?)
Tool Selection
Tool Recommendations by Stage:
| Stage | Recommended Approach |
|---|---|
| Pre-launch | Spreadsheet (Google Sheets) |
| MVP/Beta | Simple analytics (Mixpanel free, Amplitude free, PostHog) |
| Post-PMF | Full stack (Mixpanel/Amplitude + data warehouse + BI tool) |
| Scaling | Custom (Segment → warehouse → Looker/Metabase) |
Tool Comparison:
| Tool | Best For | Limitation |
|---|---|---|
| Google Analytics | Web traffic, acquisition | Weak on product analytics |
| Mixpanel | Product analytics, funnels | Can get expensive at scale |
| Amplitude | Product analytics, cohorts | Learning curve |
| PostHog | Open source, self-hosted option | Younger product |
| Heap | Auto-capture everything | Data can be messy |
| Metabase | SQL-based, self-hosted BI | Requires data warehouse |
| Looker | Enterprise BI | Complex, expensive |
6. Anti-Patterns
Metrics Mistakes:
- Tracking everything, focusing on nothing
- Vanity metrics (total signups vs. active users)
- Lagging-only metrics (revenue without leading indicators)
- No targets (data without context)
Experimentation Mistakes:
- Testing small changes on low-traffic pages
- Multiple changes in one test (can't isolate effect)
- Stopping tests early based on early results
- No hypothesis (random changes)
Retention Mistakes:
- Only looking at aggregate retention (hiding segment issues)
- Ignoring activation (retention starts at first experience)
- Not defining "active" clearly
Dashboard Mistakes:
- Dashboard nobody checks
- Real-time when weekly is sufficient
- No owners assigned to metrics
Deliverables
1. Metrics Framework Document
Create as markdown:
- North Star metric with rationale
- AARRR funnel with specific metrics
- Supporting metrics hierarchy
- Targets and owners
2. Metrics Tracker Spreadsheet
Create using xlsx skill:
- AARRR funnel metrics with weekly/monthly tracking
- Formulas for calculated metrics (conversion rates, growth rates)
- Target vs. actual comparison
- Charts for trends
3. A/B Test Plan
Create as markdown:
- Hypothesis statement
- Variants description
- Primary and guardrail metrics
- Sample size and duration calculation
- Success criteria
4. Cohort Analysis Spreadsheet
Create using xlsx skill:
- Cohort table (rows = cohorts, columns = time periods)
- Retention percentages with conditional formatting
- Retention curve visualization
- Cohort comparison charts
5. Dashboard Specification
Create as markdown:
- KPI hierarchy (executive → functional → operational)
- Metric definitions with formulas
- Visualization recommendations
- Data sources and refresh frequency
- Tool recommendation with rationale
6. SQL Query Templates
Create as markdown:
- Cohort retention query
- Funnel conversion query
- Active user calculation
- Churn identification query
Reference Files
references/metrics-frameworks.md— AARRR deep dive, North Star selection guide, metrics by business model, anti-patternsreferences/ab-testing.md— Experiment templates, sample size calculator, significance interpretation, SQL queriesreferences/retention-cohorts.md— Cohort methods, retention curves, SQL templates, benchmarks by modelreferences/dashboard-design.md— Dashboard templates, visualization guide, tool comparison
Integration with Other Skills
- Use
business-modelskill for unit economics metrics (LTV, CAC, payback) - Use
productskill for feature prioritization based on analytics - Use
go-to-marketskill for channel-specific acquisition metrics - Use
operationsskill for OKRs aligned with metrics framework - Use
fundraisingskill for investor-ready metrics presentation - Use
xlsxskill for metrics trackers and cohort spreadsheets - Use
docxskill for analytics documentation
Adapted from Linas Beliūnas's The One-Person Unicorn founder skill set.
What ships with it: 4 files
45.2 KB alongside SKILL.md
references/
- ab-testing.md9.5 KB
- dashboard-design.md15.1 KB
- metrics-frameworks.md8.8 KB
- retention-cohorts.md11.8 KB