Agent Skills: Four Fits

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:

1. Market ↔ Product - Do customers want this?
2. Product ↔ Channel - Can you reach customers efficiently?
3. Channel ↔ Model - Can your business model support acquisition costs?
4. 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

1. 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)

2. Assesses each fit independently:

   • Questions to validate fit strength
   • Evidence required
   • Common anti-patterns
   • Confidence level (Validated / Needs Work / Misaligned)

3. Identifies misalignments:

   • Which fits are blocking scale?
   • Where are the gaps?
   • What validation is needed?

4. Returns detailed assessment with:

   • Fit-by-fit analysis
   • Overall readiness score
   • Recommended fixes
   • When to scale (or not)

5. 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.