| name | four-fits |
| description | Find which fit is broken before you burn cash scaling. Brian Balfour's framework for validating sustainable growth readiness. |
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 frameworkframeworks/growth/growth-loops.md - Elena Verna on sustainable growthframeworks/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.
