Product Metrics Playbook: How to Design North Star Metrics, AARRR Funnels, and Growth Experiments

“We have tons of metrics, yet we still fail.” Imagine a product team proudly sharing its dashboard. On paper, everything looks healthy. In reality, the company is slowly bleeding. Infrastructure…

Illustration of a product metrics dashboard representing a product metrics playbook, including North Star Metrics, AARRR funnels, and growth experiments

“We have tons of metrics, yet we still fail.”

Imagine a product team proudly sharing its dashboard.

On paper, everything looks healthy. In reality, the company is slowly bleeding.

Infrastructure costs grow faster than revenue. Monetization experiments do not scale.

And despite “great engagement,” the business never reaches sustainability.

The uncomfortable truth is this:

a good product with impressive top-line metrics can still be a losing business.

When teams struggle, the root cause is rarely a lack of data. More often, it is the opposite.

In other words, teams measure activity, not progress.

If you only optimize for building a good product, you can still fail. What you need is a metric system that actively manages growth, monetization, and long-term sustainability.

Table of Contents


If you’re still not sure what product metrics actually are or how frameworks like AARRR are supposed to be used, I strongly recommend starting with this article first:

👉 https://productwithmustache.com/product-metrics-explained/

It covers the fundamentals(metrics vs KPIs vs OKRs vs North Star Metrics), how to tell vanity metrics from actionable ones, and how to use AARRR as a diagnostic framework before jumping into system-level metric design.


1. North Star Metric (NSM): How to Define the One Metric That Drives Product Growth

1) What Is a North Star Metric (NSM)? Definition, Examples, and Criteria

A North Star Metric is the single metric that best captures the value your product delivers to customers, in a way that predicts long-term business success.

It is intentionally “one.” Not because your business is simple, but because focus is rare and expensive.

A good NSM tends to have these 8 characteristics:

PropertyWhat it really means for a PM
Single metricOne number that creates focus. If you have several, you have none.
Easy to understandAny function (PM, design, engineering, sales) can explain it without translation.
Customer-centricIt represents customer value delivered, not internal activity or output.
Sustainable valueIt reflects habit formation and repeat value, not one-time spikes or campaigns.
Aligned with vision & missionWhen this metric grows, it feels like the company is fulfilling its reason to exist.
QuantitativeIt is measurable and reviewable weekly without subjective debate.
ActionableProduct, growth, and engineering teams can influence it through concrete decisions.
Leading indicatorIt moves before revenue, retention, or other lagging business metrics move.

2) How to Choose a North Star Metric: Key Questions for PMs

When you are deciding your NSM, ask:

3) North Star Metric Example: Netflix (Watch Time as a Proxy for Customer Value)

In a classic mental model, Netflix could obsess over “subscriber count” or “monthly revenue,” but many product leaders argue that a value-rooted proxy metric such as weekly watch time better reflects customer value.

Why?

Here’s the trap:

MRR can rise temporarily even when underlying customer value is weakening.

Imagine a content subscription where MRR is up, but only 10% of subscribers actually consume the content. That is a churn bomb waiting to go off.

4) Common North Star Metric Mistakes: 4 Misunderstandings PMs Should Avoid

  1. “NSM is multiple metrics.” ⇒ No. The whole point is focus.
  2. “NSM is a business metric like MRR.” ⇒ MRR and LTV/CAC are usually outcomes, not customer value.
  3. “NSM equals OKRs.” ⇒ OKRs can support NSM, but they are not the same thing.
  4. “NSM is a strategy.” ⇒ Strategy is the set of choices you make. NSM is how you measure whether those choices are working.

5) North Star Metric by Business Model: Attention vs Transaction vs Productivity

Most NSMs fall into one of three archetypes:

Key line to end this section: From here on, metric design branches based on which game your product is playing.

(1) Attention businesses

Users pay with time and repeated attention.

NSM tends to reflect:

Common mistake:

Tracking user count or revenue while attention quality declines.

(2) Transaction businesses

Users pay with money, trust, and decision effort.

NSM tends to reflect:

Common mistake:

Optimizing traffic or conversion without transaction quality.

(3) Productivity businesses

Users pay with time and workflow change.

NSM tends to reflect:

Common mistake:

Measuring usage or time spent instead of output.


2. Input Metrics (Leading Indicators): Building a North Star Metric Constellation

Picking a North Star Metric is the easy part. The hard part is making it operational, meaning:

That is where input metrics come in.

1) What Are Input Metrics? Leading Indicators That Drive the North Star Metric

An input metric is a metric that sits “upstream” of your NSM and has a meaningful impact on it.

Think of NSM as your destination and input metrics as the steering wheel, pedals, and dashboard signals that let you drive.

People often call this set the NSM constellation:

Practical rule: Keep the top-level constellation to 3–5 input metrics. More than that and you risk building a metric museum.

Common pattern:


2) Input Metrics Example: Spotify-Style NSM Constellation (Return Rate, Session Depth)

For illustration purposes, let’s assume a plausible NSM:

NSM: “Time spent listening” (per user, per week)

This is an attention-style NSM. Now we ask: what behaviors create more listening time?

A clean Level 1 constellation might be:

  1. Return rate (do users come back?)
  2. Listening time per session (how deep is each session?)

Then Level 2 levers that teams can actually work on:

What’s important here is not the exact Spotify choices. It’s the structure:


A strong metric system eventually links:

Input metrics → NSM → Business outcomes

For example, you might discover something like:

“Users who listen at least 2 hours per week churn 30% less.”

That kind of relationship is powerful because it turns NSM into a business predictor. But this is where many teams accidentally lie to themselves.

How to validate responsibly:


3. AARRR Metrics Framework: Diagnosing Acquisition, Activation, Retention, Revenue, and Referral

AARRR is not a checklist of metrics you must track.

It is a diagnostic lens for understanding where your product is stuck and which metrics deserve attention right now.

When teams misuse AARRR, they usually do one of two things:

The right way to use AARRR is problem-first:

“Given our current situation, which stage is broken, and which metrics help us fix it?”


1) What AARRR stands for

AARRR breaks the user journey into five questions:

StageCore question
AcquisitionHow do users find us?
ActivationHow do users first experience value?
RetentionWhy do users come back?
RevenueDo users pay, and how sustainably?
ReferralDo users bring others?

Two supporting layers sit across all stages:

2) Acquisition metrics: “We don’t have enough users”

When traffic is low or growth is flat at the top of the funnel, resist the urge to redesign onboarding or pricing. You first need users to arrive.

Core acquisition metrics:

How PMs misuse these metrics:

Good diagnostic question:

Which channel brings users who actually activate later?


3) Activation metrics: “Users come, but don’t feel value”

This is one of the most common failure modes. Users sign up, poke around, and disappear.

Activation is about first value, not first click.

Core activation metrics:

MetricMeaning
Time to Value (TTV)The time it takes for a new user to experience the product’s core value for the first time. Shorter TTV usually means faster activation.
Onboarding completion rateThe percentage of users who complete the intended onboarding flow (e.g., signup steps, tutorial, initial setup).
Activation rateThe percentage of new users who reach a clearly defined “activated” state that indicates real value realization.
Paid conversion rateThe percentage of users who convert to paid. Useful as an early signal, but not proof of long-term value or retention.
PQA (Product Qualified Accounts)Accounts that match the ideal customer profile and demonstrate meaningful product usage, indicating high revenue potential.
PQL (Product Qualified Leads)Individual users or leads who show strong product engagement signals and are likely to convert with sales or marketing follow-up.

Key concept: Product Qualified

A PQA or PQL is not just “interested.” It is defined internally as a user or account that matches your ideal customer profile and demonstrates meaningful product usage.


4) Retention metrics: “Users try once and never return”

Retention tells you whether your product deserves to exist repeatedly in a user’s life.

Core retention metrics:

MetricMeaning
Churn rateThe percentage of users or customers who stop using the product during a given period. A lagging but critical signal of retention failure.
Retention rate (cohort-based)The percentage of users in a specific cohort who continue using the product over time. Reveals habit formation and product stickiness.
Renewal rateThe percentage of customers who renew their subscription or contract at the end of a billing cycle. Especially important for SaaS and enterprise products.
Customer lifetimeThe average length of time a customer remains active before churning. Indicates durability of product value.
Customer Health ScoreA composite score combining usage, engagement, and qualitative signals to estimate churn risk or expansion potential.
Product / feature adoption rateThe percentage of users who actively use a product or specific feature. Helps identify which features actually drive retention.

Common PM mistake:

Retention problems are rarely global. They are usually segment-specific.


5) Revenue metrics: “People use it, but revenue is weak”

This is where many “loved but unprofitable” products get stuck.

Core revenue metrics:

MetricMeaning
ARPA (Average Revenue per Account)The average revenue generated per customer account over a given period. Useful for comparing monetization efficiency across segments.
CLV (Customer Lifetime Value)The total revenue a customer is expected to generate over their entire relationship with the product. A key metric for long-term sustainability.
Customer profitabilityRevenue minus all costs associated with serving a customer. Reveals whether growth is actually profitable.
MRR (Monthly Recurring Revenue)Predictable recurring revenue generated each month from subscriptions. A core reporting metric for subscription businesses.
Expansion revenueAdditional revenue from existing customers through upsells, cross-sells, or seat expansion. Indicates account growth beyond initial conversion.
Net revenue & revenue churnNet revenue accounts for expansion and contraction, while revenue churn measures lost recurring revenue. Together, they show true revenue health.
ACV (Average Contract Value)The average monetary value of a customer contract. Important for understanding deal size, sales efficiency, and revenue predictability.

Important nuance:

Revenue metrics should not be used alone to judge product health. They need context from retention and activation.


6) Referral metrics: “Growth has stalled”

Referral metrics matter when your core loop is healthy but growth slows.

Core referral metrics:

MetricMeaning
Virality coefficientThe average number of new users each existing user brings in. A value above 1 indicates self-sustaining growth.
Customer referral rateThe percentage of users who actively refer others. Shows how widespread referral behavior is across the user base.
Referral conversion rateThe percentage of referred users who actually sign up or activate. Measures referral quality, not just volume.
NPS (Net Promoter Score)A survey-based score indicating how likely users are to recommend the product. Reflects sentiment, not guaranteed behavior.

High NPS without referral behavior often means users like you, but not enough to change their behavior.


7. AARRR Metrics by Stage: What to Focus on Before vs After Product-Market Fit (PMF)

AARRR shows the full user journey, but it does not mean every stage deserves equal attention at all times.

Trying to optimize Acquisition, Activation, Retention, Revenue, and Referral simultaneously is not strategy. It is distraction.

Where you should focus depends on your business model and your current stage. A metric that signals progress in one context can be meaningless or even harmful in another.

(1) There is no universal “good” number

Healthy ranges vary widely based on:

Blind benchmarking is dangerous.

Applying SaaS churn benchmarks to a marketplace, or late-stage growth targets to a pre-PMF product, leads teams to optimize the wrong problems.

A metric without context is just a number.

(2) Growth rate only matters after product-market fit

In early-stage, consumer-focused startups, Y Combinator often suggests:

These benchmarks are useful only after product-market fit.

Before PMF:

In early stages, growth is not the goal.

Learning and retention are.

(3) What “progress” means changes by stage

Different stages demand different AARRR focus:

AARRR helps you diagnose where you are stuck.

Business model and stage decide where you should dig first.

AARRR is a map, not a to-do list.

Focus on the stage that limits progress right now, not the one that looks impressive on a dashboard.


4. Metric Selection Framework: How to Choose Metrics That Don’t Break Your Product

At this point, you probably have a long list of possible metrics.

The real danger is not missing metrics. It is choosing the wrong ones and rewarding the wrong behavior.

This framework helps you filter metrics before they earn a permanent place on your dashboard.

Before adopting any metric, it should pass three filters:

  1. Is it a good metric?
  2. Do we understand what type of metric it is?
  3. Do we know how it could be gamed?

1) Good Product Metrics: 6 Criteria for Decision-Making (Not Reporting)

A metric does not need to be perfect.

It needs to be useful for decision-making.

ConditionWhat this means in practice
ComparableYou can compare it over time, across segments, and between experiments. No comparison, no decision.
UnderstandableAnyone on the team can explain what it means and what action it implies.
Ratio / rate-basedRates add context. Conversion rate beats total conversions. Retention rate beats total users.
Behavior-changingIt helps decide what to try next, not just whether you “won.”
Positive for customer and businessOptimizing it improves customer value and business health together.
Paired by designIt has a built-in counter-metric to prevent shortcuts and distortion.

2) Why treating all metrics as equal breaks decision-making

Misuse happens when teams treat all metrics as equal.

They are not.

Understanding the type of metric prevents wrong conclusions.

(1) Qualitative vs Quantitative

Metric typeWhat it answersTypical examplesWhen it is most useful
QuantitativeWhat happened? How much? How often?DAU, retention rate, conversion rate, churn rateTracking trends, comparing cohorts, measuring experiment impact
QualitativeWhy did it happen? What are users thinking?User interviews, open-ended survey responses, usability test feedbackUnderstanding motivation, diagnosing drop-offs, generating hypotheses

Analytics shows behavior. Interviews explain motivation.

You need both.

How to use them together

SituationQuantitative signalQualitative follow-up
Activation dropsActivation rate ↓Interview users who failed onboarding
Retention declinesCohort retention ↓Ask churned users why they left
Feature underperformsFeature adoption ↓Observe how users attempt the task

(2) Vanity vs actionable

Vanity metrics grow even when nothing improves.

Vanity metricWhy it failsActionable metricWhy it works
Total sign-upsAlways goes upUsers activated within 7 daysDirectly tied to onboarding
Total active usersGrows by defaultWeekly active users per cohortShows real retention
Page viewsInflated by SEOSessions with core actionMeasures value delivered

Key idea:

If a metric does not suggest a next action, it is vanity.

(3) Exploratory vs reporting

Metric typePurposeTypical examplesWhen it is most useful
Reporting metricsConfirm and monitor known performanceMRR, DAU, churn rate, revenue growthOngoing operations, weekly reviews, stakeholder reporting
Exploratory metricsDiscover unknown patterns and leverageFunnel drop-offs, feature usage paths, session replaysEarly-stage products, diagnosing problems, generating experiment ideas

Early-stage products should favor exploratory metrics.

This is where insight comes from.

How to use them together

SituationReporting metricExploratory metric
Revenue stagnatesMRR flatFunnel analysis by segment
Activation is lowActivation rateOnboarding step drop-off analysis
Feature adoption unclearFeature usage rateClick paths and task completion analysis

(4) Leading vs lagging

Metric typeWhat it tells youTypical examplesWhy it matters
Lagging metricsWhat already happenedRevenue, churn rate, MRR, renewalsUseful for reporting and accountability, but too late for prevention
Leading metricsWhat is likely to happenActivation rate, usage frequency, customer complaints volumeEnable early intervention and proactive decision-making

Churn tells you damage already happened.

Customer complaints volume warns you before it happens.

How to use them together

SituationLagging metricLeading metric
Customer churn increasesMonthly churn rateDeclining usage frequency
Revenue dropsMRRActivation rate of new users
Support issues escalateChurnIncoming complaints volume

(5) Correlated vs causal

Metric relationshipWhat it meansTypical exampleRisk if misunderstood
CorrelatedTwo metrics move together, but one does not necessarily cause the otherIce cream sales ↑ and drowning incidents ↑ in summerTeams act on the wrong lever and waste effort
CausalOne metric directly influences anotherFaster Time to Value → higher retentionEnables confident prioritization and scaling

Metrics often move together without causing each other.

For example, ice cream sales and drowning both increase in summer. Summer causes both. Treat correlation as a hypothesis, not truth. Causality must be proven through experiments.

How to interpret correlations safely

ObservationWrong conclusionBetter interpretation
Feature usage ↑, retention ↑“This feature causes retention”Usage may be a symptom of existing engagement
NPS ↑, referrals ↑“High NPS drives growth”Both may reflect underlying satisfaction
Engagement ↑, revenue ↑“Engagement equals monetization”A third factor may influence both

How to move from correlation to causation

  1. Treat correlation as a hypothesis, not a decision
    Correlation suggests a possible relationship, but it is not proof. Use it as a starting point for investigation, not as a basis for action.
  2. Segment users to remove obvious confounders
    Break users into meaningful segments (e.g., new vs. returning, free vs. paid, light vs. power users) to check whether the relationship still holds after removing obvious biases.
  3. Run controlled experiments or A/B tests
    Change one variable at a time and observe its impact. Controlled experiments are the most reliable way to establish causation.
  4. Validate with qualitative research (interviews, surveys)
    Use qualitative methods to confirm why the change occurred and whether it reflects real user value, not just statistical movement.

3) Paired Metrics (Guardrail Metrics): Preventing Gaming, Goal Distortion, and Local Optimization

Metrics are powerful tools, but they become dangerous the moment they turn into targets.

When teams are rewarded on a single number, they will optimize that number, even if it quietly damages the product, customers, or long-term growth.

(1) Common patterns of goal distortion

Goal distortion rarely comes from bad intentions. It comes from optimizing a single metric without guardrails.

Across teams and industries, the same failure patterns appear again and again.

Three classic distortion patterns:

Optimized metricWhat improves on paperWhat actually breaks
New contracts closedSales velocityCustomer quality, long-term retention
Features shippedPerceived productivityCode quality, future development speed
Tickets resolvedSupport efficiencyCustomer trust, CSAT, relationship quality

In every case, the metric moves in the “right” direction.

And in every case, the product or business quietly degrades elsewhere.

What looks like progress in a dashboard often hides long-term damage in reality.

(2) Why does goal distortion happen?

Because metrics shape incentives.

If a metric is tied to performance reviews, bonuses, or visibility, people will optimize it. This is human nature, not a moral failure.

The real problem is metric design without safeguards.

(3) The Principle of Pairing Indicators

To prevent goal distortion, no metric should stand alone.

For every primary metric you optimize, ask one question:

“What could break if we push this too hard?”

Then measure that risk explicitly.

This is the Principle of Pairing Indicators.

(4) Three universal pairing rules

Most safe metric systems follow these patterns:

  1. Short-term gain ↔ long-term cost
  2. Quantity ↔ quality
  3. Process ↔ outcome

These pairings turn metrics from blunt instruments into control systems.

Metric pairs examples:

Primary metricPaired metric (safety check)What it protects
New contracts completedExisting customer retentionRevenue quality
Features shippedBugs per releaseProduct quality
Tickets resolvedCSAT / NPSCustomer trust
Activation rateTime to valueShallow onboarding
Referral invites sentReferral conversion rateFake virality

Pairing does not slow teams down. It prevents teams from winning the metric while losing the business.


5. E-commerce: Conversion is not the problem you think it is

1) Typical situation

An e-commerce team sees flat conversion and immediately reacts by:

Conversion barely moves.

(1) Common mistake

(2) Metric set that actually helps

QuestionMetric
Are users price-sensitive or trust-sensitive?Conversion rate by price bucket
Where does intent break?View → cart → checkout step drop-off
Is demand unmet?Search queries with no results
Is higher conversion worth it?Conversion rate paired with AOV

(3) Why this works

In e-commerce, low conversion often reflects:

Improving conversion without tracking order value and intent signals often increases low-quality orders or returns.

In e-commerce, conversion is usually a lagging result, not the root cause.

2) Redefine Success with Metrics

(1) Business goal: Enable confident, high-intent purchases.

(2) Example North Star Metric (NSM)

This captures both demand and trust, without over-indexing on traffic.

(3) Level-1 input metrics (primary drivers)

DriverWhy it matters
Product view → purchase conversionMeasures purchase confidence
Average order value (AOV)Captures monetization quality
Search success rateReveals unmet demand
Cart abandonment rateSignals friction or trust issues

(4) Level-2 product levers (what teams can act on)

(5) Key pairing


6. SaaS: Revenue is not a pricing problem (until activation works)

1) Typical situation

A SaaS team sees weak revenue growth and immediately reacts by:

Revenue bumps briefly, then churn increases.

(1) Common mistake

(2) Metric set that actually helps

QuestionMetric
Do users reach core value?Time to Value (TTV)
Who activates meaningfully?Activation rate by segment
Are we attracting the right users?PQL / PQA rate
Is revenue durable?Activation ↔ 90-day retention

(3) Why this works

In SaaS, revenue quality is determined before payment.

If users do not reach value quickly and deeply, pricing changes only accelerate churn.

Revenue problems usually start as activation problems, not monetization problems.

2) Redefine Success with Metrics

(1) Business goal: Turn product usage into durable, expanding revenue.

(2) Example North Star Metric (NSM)

Not all activity matters. Activated accounts do.

(3) Level-1 input metrics (primary drivers)

DriverWhy it matters
Activation ratePredicts retention and revenue
Time to Value (TTV)Determines early drop-off
PQL / PQA rateFilters for revenue-worthy usage
Expansion revenue rateMeasures account growth

(4) Level-2 product levers (what teams can act on)

(5) Key pairing


7. Mobile Apps: Monetization does not create retention

1) Typical situation

A mobile app team celebrates strong install growth and focuses on:

Day-1 retention drops. Paid conversion stays flat.

(1) Common mistake

(2) Metric set that actually helps

QuestionMetric
Do users come back naturally?Day-1 / Day-7 retention
Is a habit forming?Sessions per user per day
What predicts LTV early?First-session core actions
Is growth sustainable?LTV ↔ CAC

(3) Why this works

In mobile, churn is the default.

Without early habit formation, monetization reshuffles a shrinking base.

Revenue is a byproduct of retention, not a lever that creates it.

2) Redefine Success with Metrics

(1) Business goal: Build repeatable habits at scale.

(2) Example North Star Metric (NSM)

Installs mean nothing without repeat behavior.

(3) Level-1 input metrics

DriverWhy it matters
Early retentionPredicts survival
Session frequencySignals habit formation
Core action completionPredicts LTV
LTV ↔ CACEnables scaling

(4) Level-2 product levers

(5) Key pairing


8. Media: Traffic is noise without return

1) Typical situation

A media team reports growing page views and long session times.

Traffic looks healthy, but return visits remain flat.

(1) Common mistake

(2) Metric set that actually helps

QuestionMetric
Is attention intentional?Interaction rate + scroll depth
Does content bring users back?Return visit rate
Is time valuable or confusing?Engaged time ↔ bounce
What actually matters?Repeat consumption by content

(3) Why this works

Long time on page can mean value — or confusion.

Only return behavior distinguishes the two.

2) Redefine Success with Metrics

(1) Business goal: Deliver valuable, intentional attention.

(2) Example North Star Metric (NSM)

Traffic without return is noise.

(3) Level-1 input metrics

DriverWhy it matters
Return visit rateSignals real value
Engaged timeMeasures depth
Content interactionIndicates intent
Content repeatabilityPredicts loyalty

(4) Level-2 product levers

(5) Key pairing


9. UGC Platforms: Creation is the fragile side of the system

1) Typical situation

A UGC platform grows DAU and content volume.

Meanwhile:

(1) Common mistake

(2) Metric set that actually helps

QuestionMetric
Where do creators fail?Creation flow drop-off
Are creators staying?Creator retention
Is supply concentrated?Contribution distribution
Is the system safe?Spam / abuse rate

(3) Why this works

UGC platforms run on a small creator minority.

Burn them out, and growth collapses later.

2) Redefine Success with Metrics

(1) Business goal: Sustain healthy creation and consumption.

(2) Example North Star Metric (NSM)

Creation is the supply side of value.

(3) Level-1 input metrics

DriverWhy it matters
Creator activationGrows supply
Creator retentionProtects ecosystem
Creation completionIdentifies friction
Content quality signalsMaintains trust

(4) Level-2 product levers

(5) Key pairing


10. Marketplaces: Growth fails when balance breaks

1) Typical situation

A marketplace sees slowing growth and reacts by:

Transaction success keeps falling.

(1) Common mistake

(2) Metric set that actually helps

QuestionMetric
Is the market balanced?Supply ↔ demand ratio
Where does liquidity fail?Search → transaction completion
Who really matters?Top buyer/seller contribution
Is value concentrated?Category-level GMV

(3) Why this works

Marketplaces break when balance breaks, not when traffic drops.

More users without liquidity increase frustration.

2) Redefine Success with Metrics

(1) Business goal: Maintain balanced, liquid transactions.

(2) Example North Star Metric (NSM)

Transactions reflect real liquidity.

(3) Level-1 input metrics

DriverWhy it matters
Supply-demand balancePrevents dead markets
Transaction successMeasures liquidity
Time to matchReveals friction
Power-user contributionShapes outcomes

(4) Level-2 product levers

(5) Key pairing


11. Experiment-Driven Growth System: Instrumentation, Growth Equation, and A/B Testing Loop

Metrics only matter if they lead to decisions, experiments, and learning. This section connects everything so far into a repeatable operating system.

1) Growth Equation: How to Model Product Growth with a Metrics Formula

Before running experiments, you must agree on how growth actually happens in your product.

This is where a growth equation helps.

Examples:

(1) Subscription business

(Traffic × Email conversion × Activation rate × Paid conversion)
+ Retained subscribers
+ Reactivated subscribers
= Subscription growth

(2) Marketplace (eBay-style)

Active sellers × Listings per seller × Active buyers × Successful transactions
= GMV growth

(3) Commerce platform (Amazon-style)

Category expansion × Inventory depth × Traffic per product
× Purchase conversion × Average order value × Repeat purchases
= Revenue growth

The goal is not mathematical perfection. The goal is clarity on leverage.

A good growth equation often naturally points to your NSM.

For a messenger app, “messages sent” is often more meaningful than “active users,” because it directly reflects delivered value.

If you cannot write your growth equation on one slide, you probably do not agree on how growth works.


2) Product Analytics Instrumentation: Event Tracking, Logging, and Data Quality Basics

A growth equation is useless if you cannot measure it.

Instrumentation means:

But quantitative data alone is not enough.

Analytics shows behavioral patterns, not motivations.

To understand why metrics move, you need:


3) Growth Experiments: Increasing Learning Velocity with Small, Fast Tests

Most experiments fail.

High-performing teams accept this and optimize for learning speed, not win rate.

Important principles:


4) Experiment Process: Analyze → Ideate → Prioritize (ICE) → Experiment

A practical loop looks like this:

StepFocusWhat it includes
AnalyzeUnderstand the problemUser behavior, personas, funnel and drop-off points
IdeateExpand solution spaceGenerate many ideas without evaluation or filtering
Prioritize (ICE)Decide what to test first– Impact (expected effect)

What every experiment report should include:

12. Product Metrics Checklist: How to Tell If Your Metric System Is Actually Working

Use this checklist when designing metrics, reviewing dashboards, or resetting your product KPIs.

1) North Star Metric (Direction)

👉 If any box is unchecked, fix the NSM first.

2) Input Metrics & Constellation (Control)

👉 If input metrics feel like excuses instead of levers, the metric system likely needs redesign.

3) AARRR Focus (Diagnosis)

👉 If everything feels important, the problem is not defined.

4) Metric Quality (Signal vs Noise)

👉 Metrics that only “look good” belong in reports, not decisions.

5) Metric Pairing (Anti-Gaming)

Examples:

👉 Unpaired metrics are highly likely to be gamed over time.

6) Experiments & Learning Loop (Execution)

👉 Metrics without experiments quickly turn into decoration.

7) Final Sanity Check

Ask this out loud:

“If this metric moves, what will we build or change next week?”

If the answer is unclear, the metric is for reporting, not operating.

A strong metric system is not about dashboards. It is about direction and behavior.

Metrics are not reports. They are an operating system that changes what the team does next.

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