Four Fits
Before you scale, all four fits must work. If one is broken, scaling fails.
Most companies scale too early. They have product-market fit and think they're ready. They're not. You need all four:
- •Market ↔ Product - Do customers want this?
- •Product ↔ Channel - Can you reach customers efficiently?
- •Channel ↔ Model - Can your business model support acquisition costs?
- •Model ↔ Market - Can you monetize this market profitably?
One broken fit = don't scale yet. Fix it first.
Philosophy: "All four fits must align for $100M+ growth. Scaling with misaligned fits burns cash." - Brian Balfour
Entry Point
When this skill is invoked, start with:
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FOUR FITS ASSESSMENT
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Before you scale, all four fits must work.
What do you want to do?
1. Full assessment
→ Evaluate all four fits
2. Diagnose growth blocker
→ Find which fit is broken
3. Pre-scale validation
→ Checklist before spending
4. Specific market segment
→ Analyze fit for new segment
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Usage
/four-fits
Examples:
- •
/four-fits- Full assessment of current state - •
/four-fits --validate- Pre-scale validation checklist - •
/four-fits --diagnose- Identify which fit is blocking growth - •
/four-fits --market "SMB SaaS"- Specify market explicitly
What Happens
- •
Gathers context about your product:
- •What's your market? (SMB, enterprise, consumer)
- •What's your product? (feature set, positioning)
- •What's your primary channel? (paid, viral, content, sales)
- •What's your business model? (SaaS, marketplace, freemium, transaction)
- •
Assesses each fit independently:
- •Questions to validate fit strength
- •Evidence required
- •Common anti-patterns
- •Confidence level (Validated / Needs Work / Misaligned)
- •
Identifies misalignments:
- •Which fits are blocking scale?
- •Where are the gaps?
- •What validation is needed?
- •
Returns detailed assessment with:
- •Fit-by-fit analysis
- •Overall readiness score
- •Recommended fixes
- •When to scale (or not)
- •
Provides validation activities to de-risk each fit
Four Fits Deep Dive
Fit #1: Market ↔ Product
The question: Do customers want this?
Validation signals:
- •High retention (>80% for SaaS)
- •Strong NPS (>40)
- •PMF survey >40% "very disappointed"
- •Organic word-of-mouth
- •Customers choose you over alternatives
Anti-patterns:
- •Low retention (<60%)
- •Building features customers don't use
- •Winning on price, not value
See: /pmf-survey for validation
Fit #2: Product ↔ Channel
The question: Can we reach customers efficiently through this channel?
Validation signals:
- •Customers discover you naturally
- •CAC is sustainable (<1/3 of LTV)
- •Acquisition is repeatable and scalable
- •Product is suited to channel (e.g., viral product + viral channel)
Anti-patterns:
- •CAC > LTV (unsustainable)
- •Channel is saturated (CPCs rising)
- •Product onboarding too slow for channel
- •Can't scale channel 10x
Channel types:
- •Paid (Google Ads, Facebook, etc.)
- •Viral (referrals, word-of-mouth)
- •Content (SEO, owned media)
- •Sales (outbound, inside sales)
Fit #3: Channel ↔ Model
The question: Does our business model support acquisition costs?
Validation signals:
- •LTV/CAC > 3 (healthy)
- •Payback period acceptable (< 12 months)
- •Gross margins support channel costs
- •Can profitably acquire at scale
Anti-patterns:
- •LTV/CAC < 2 (unprofitable)
- •Payback > 18 months (too long)
- •Thin margins can't support CAC
- •Model doesn't scale with volume
See: /ai-cost-check for cost modeling
Fit #4: Model ↔ Market
The question: Can we monetize this market profitably?
Validation signals:
- •Market can afford your pricing
- •TAM is large enough for ambitions
- •Can expand within accounts
- •Model aligns with market buying behavior
Anti-patterns:
- •Market can't afford pricing (too expensive for segment)
- •TAM too small for goals
- •No expansion revenue (one-and-done)
- •Mismatch in sales cycle vs model
Diagnostic Mode
/four-fits --diagnose
Helps identify WHICH fit is blocking growth:
Symptoms → Diagnosis:
Low retention, high churn
→ Market-Product fit issue
→ Run: /pmf-survey
High CAC, can't scale acquisition → Product-Channel fit issue → Consider: Different channel or improve activation
Unprofitable customer acquisition
→ Channel-Model fit issue
→ Run: /ai-cost-check or raise prices
Can't expand, limited TAM → Model-Market fit issue → Consider: Different market segment or business model
Related Commands
- •
/pmf-survey- Validate Market-Product fit specifically - •
/growth-loops- Design Product-Channel fit via loops - •
/lno-prioritize- Prioritize work to fix misaligned fits - •
/ai-cost-check- Validate Channel-Model economics
Learn More
Full frameworks:
- •
frameworks/growth/four-fits.md- Brian Balfour's complete framework - •
frameworks/growth/growth-loops.md- Elena Verna on sustainable growth - •
frameworks/measurement/pmf-survey.md- Validate Market-Product fit
Framework: Four Fits (Brian Balfour) Best for: Validating sustainable scaling readiness Key insight: "All four fits must align for $100M+ growth. Scaling with misaligned fits burns cash." Remember: Fix fits in order - Market-Product first, then Product-Channel, then Channel-Model, then Model-Market. Don't skip ahead.