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name: market-sizing-analysis

description: Calculate TAM/SAM/SOM for market opportunities using top-down, bottom-up, and value theory methodologies. Use this skill when sizing markets, estimating addressable revenue, validating market opportunity for a new venture, or building investor-ready market analysis for a startup pitch or business plan.

version: 1.0.0

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# Market Sizing Analysis

Comprehensive market sizing methodologies for calculating Total Addressable Market (TAM), Serviceable Available Market (SAM), and Serviceable Obtainable Market (SOM) for startup opportunities.

## Overview

Market sizing provides the foundation for startup strategy, fundraising, and business planning. Calculate market opportunity using three complementary methodologies: top-down (industry reports), bottom-up (customer segment calculations), and value theory (willingness to pay).

## Core Concepts

### The Three-Tier Market Framework

**TAM (Total Addressable Market)**

- Total revenue opportunity if achieving 100% market share

- Defines the universe of potential customers

- Used for long-term vision and market validation

- Example: All email marketing software revenue globally

**SAM (Serviceable Available Market)**

- Portion of TAM targetable with current product/service

- Accounts for geographic, segment, or capability constraints

- Represents realistic addressable opportunity

- Example: AI-powered email marketing for e-commerce in North America

**SOM (Serviceable Obtainable Market)**

- Realistic market share achievable in 3-5 years

- Accounts for competition, resources, and market dynamics

- Used for financial projections and fundraising

- Example: 2-5% of SAM based on competitive landscape

### When to Use Each Methodology

**Top-Down Analysis**

- Use when established market research exists

- Best for mature, well-defined markets

- Validates market existence and growth

- Starts with industry reports and narrows down

**Bottom-Up Analysis**

- Use when targeting specific customer segments

- Best for new or niche markets

- Most credible for investors

- Builds from customer data and pricing

**Value Theory**

- Use when creating new market categories

- Best for disruptive innovations

- Estimates based on value creation

- Calculates willingness to pay for problem solution

- ## Three-Methodology Framework

- ### Methodology 1: Top-Down Analysis

- Start with total market size and narrow to addressable segments.

- **Process:**

- 1. Identify total market category from research reports

- 2. Apply geographic filters (target regions)

- 3. Apply segment filters (target industries/customers)

- 4. Calculate competitive positioning adjustments

- **Formula:**

- ```

- TAM = Total Market Category Size

- SAM = TAM × Geographic % × Segment %

- SOM = SAM × Realistic Capture Rate (2-5%)

- ```

- **When to use:** Established markets with available research (e.g., SaaS, fintech, e-commerce)

- **Strengths:** Quick, uses credible data, validates market existence

- **Limitations:** May overestimate for new categories, less granular

- ### Methodology 2: Bottom-Up Analysis

- Build market size from customer segment calculations.

- **Process:**

- 1. Define target customer segments

- 2. Estimate number of potential customers per segment

- 3. Determine average revenue per customer

- 4. Calculate realistic penetration rates

- **Formula:**

- ```

- TAM = Σ (Segment Size × Annual Revenue per Customer)

- SAM = TAM × (Segments You Can Serve / Total Segments)

- SOM = SAM × Realistic Penetration Rate (Year 3-5)

- ```

- **When to use:** B2B, niche markets, specific customer segments

- **Strengths:** Most credible for investors, granular, defensible

- **Limitations:** Requires detailed customer research, time-intensive

- ### Methodology 3: Value Theory

- Calculate based on value created and willingness to pay.

- **Process:**

- 1. Identify problem being solved

- 2. Quantify current cost of problem (time, money, inefficiency)

- 3. Calculate value of solution (savings, gains, efficiency)

- 4. Estimate willingness to pay (typically 10-30% of value)

- 5. Multiply by addressable customer base

- **Formula:**

- ```

- Value per Customer = Problem Cost × % Solved by Solution

- Price per Customer = Value × Willingness to Pay % (10-30%)

- TAM = Total Potential Customers × Price per Customer

- SAM = TAM × % Meeting Buy Criteria

- SOM = SAM × Realistic Adoption Rate

- ```

- **When to use:** New categories, disruptive innovations, unclear existing markets

- **Strengths:** Shows value creation, works for new markets

- **Limitations:** Requires assumptions, harder to validate

- ## Step-by-Step Process

- ### Step 1: Define the Market

- Clearly specify what market is being measured.

- **Questions to answer:**

- - What problem is being solved?

- - Who are the target customers?

- - What's the product/service category?

- - What's the geographic scope?

- - What's the time horizon?

- **Example:**

- - Problem: E-commerce companies struggle with email marketing automation

- - Customers: E-commerce stores with >$1M annual revenue

- - Category: AI-powered email marketing software

- - Geography: North America initially, global expansion

- - Horizon: 3-5 year opportunity

- ### Step 2: Gather Data Sources

- Identify credible data for calculations.

- **Top-Down Sources:**

- - Industry research reports (Gartner, Forrester, IDC)

- - Government statistics (Census, BLS, trade associations)

- - Public company filings and earnings

- - Market research firms (Statista, CB Insights, PitchBook)

- **Bottom-Up Sources:**

- - Customer interviews and surveys

- - Sales data and CRM records

- - Industry databases (LinkedIn, ZoomInfo, Crunchbase)

- - Competitive intelligence

- - Academic research

- **Value Theory Sources:**

- - Customer problem quantification

- - Time/cost studies

- - ROI case studies

- - Pricing research and willingness-to-pay surveys

- ### Step 3: Calculate TAM

- Apply chosen methodology to determine total market.

- **For Top-Down:**

- 1. Find total category size from research

- 2. Document data source and year

- 3. Apply growth rate if needed

- 4. Validate with multiple sources

- **For Bottom-Up:**

- 1. Count total potential customers

- 2. Calculate average annual revenue per customer

- 3. Multiply to get TAM

- 4. Break down by segment

- **For Value Theory:**

- 1. Quantify total addressable customer base

- 2. Calculate value per customer

- 3. Estimate pricing based on value

- 4. Multiply for TAM

- ### Step 4: Calculate SAM

- Narrow TAM to serviceable addressable market.

- **Apply Filters:**

- - Geographic constraints (regions you can serve)

- - Product limitations (features you currently have)

- - Customer requirements (size, industry, use case)

- - Distribution channel access

- - Regulatory or compliance restrictions

- **Formula:**

- ```

- SAM = TAM × (% matching all filters)

- ```

- **Example:**

- - TAM: $10B global email marketing

- - Geographic filter: 40% (North America)

- - Product filter: 30% (e-commerce focus)

- - Feature filter: 60% (need AI capabilities)

- - SAM = $10B × 0.40 × 0.30 × 0.60 = $720M

- ### Step 5: Calculate SOM

- Determine realistic obtainable market share.

- **Consider:**

- - Current market share of competitors

- - Typical market share for new entrants (2-5%)

- - Resources available (funding, team, time)

- - Go-to-market effectiveness

- - Competitive advantages

- - Time to achieve (3-5 years typically)

- **Conservative Approach:**

- ```

- SOM (Year 3) = SAM × 2%

- SOM (Year 5) = SAM × 5%

- ```

- **Example:**

- - SAM: $720M

- - Year 3 SOM: $720M × 2% = $14.4M

- - Year 5 SOM: $720M × 5% = $36M

- ### Step 6: Validate and Triangulate

- Cross-check using multiple methods.

- **Validation Techniques:**

- 1. Compare top-down and bottom-up results (should be within 30%)

- 2. Check against public company revenues in space

- 3. Validate customer count assumptions

- 4. Sense-check pricing assumptions

- 5. Review with industry experts

- 6. Compare to similar market categories

- **Red Flags:**

- - TAM that's too small (< $1B for VC-backed startups)

- - TAM that's too large (unsupported by data)

- - SOM that's too aggressive (> 10% in 5 years for new entrant)

- - Inconsistency between methodologies (> 50% difference)

- ## Industry-Specific Considerations

- ### SaaS Markets

- **Key Metrics:**

- - Number of potential businesses in target segment

- - Average contract value (ACV)

- - Typical market penetration rates

- - Expansion revenue potential

- **TAM Calculation:**

- ```

- TAM = Total Target Companies × Average ACV × (1 + Expansion Rate)

- ```

- ### Marketplace Markets

- **Key Metrics:**

- - Gross Merchandise Value (GMV) of category

- - Take rate (% of GMV you capture)

- - Total transactions or users

- **TAM Calculation:**

- ```

- TAM = Total Category GMV × Expected Take Rate

- ```

- ### Consumer Markets

- **Key Metrics:**

- - Total addressable users/households

- - Average revenue per user (ARPU)

- - Engagement frequency

- **TAM Calculation:**

- ```

- TAM = Total Users × ARPU × Purchase Frequency per Year

- ```

- ### B2B Services

- **Key Metrics:**

- - Number of target companies by size/industry

- - Average project value or retainer

- - Typical buying frequency

- **TAM Calculation:**

- ```

- TAM = Total Target Companies × Average Deal Size × Deals per Year

- ```

- ## Presenting Market Sizing

- ### For Investors

- **Structure:**

- 1. Market definition and problem scope

- 2. TAM/SAM/SOM with methodology

- 3. Data sources and assumptions

- 4. Growth projections and drivers

- 5. Competitive landscape context

- **Key Points:**

- - Lead with bottom-up calculation (most credible)

- - Show triangulation with top-down

- - Explain conservative assumptions

- - Link to revenue projections

- - Highlight market growth rate

- ### For Strategy

- **Structure:**

- 1. Addressable customer segments

- 2. Prioritization by opportunity size

- 3. Entry strategy by segment

- 4. Expected penetration timeline

- 5. Resource requirements

- **Key Points:**

- - Focus on SAM and SOM

- - Show segment-level detail

- - Connect to go-to-market plan

- - Identify expansion opportunities

- - Discuss competitive positioning

- ## Common Mistakes to Avoid

- **Mistake 1: Confusing TAM with SAM**

- - Don't claim entire market as addressable

- - Apply realistic product/geographic constraints

- - Be honest about serviceable market

- **Mistake 2: Overly Aggressive SOM**

- - New entrants rarely capture > 5% in 5 years

- - Account for competition and resources

- - Show realistic ramp timeline

- **Mistake 3: Using Only Top-Down**

- - Investors prefer bottom-up validation

- - Top-down alone lacks credibility

- - Always triangulate with multiple methods

- **Mistake 4: Cherry-Picking Data**

- - Use consistent, recent data sources

- - Don't mix methodologies inappropriately

- - Document all assumptions clearly

- **Mistake 5: Ignoring Market Dynamics**

- - Account for market growth/decline

- - Consider competitive intensity

- - Factor in switching costs and barriers

- ## Quick Start

+ ## Detailed patterns and worked examples

- To perform market sizing analysis:

+ Detailed pattern documentation lives in `references/details.md`. Read that file when the navigation tier above is insufficient.

- 1. **Define the market** - Problem, customers, category, geography

- 2. **Choose methodology** - Bottom-up (preferred) or top-down + triangulation

- 3. **Gather data** - Industry reports, customer data, competitive intelligence

- 4. **Calculate TAM** - Apply methodology formula

- 5. **Narrow to SAM** - Apply product, geographic, segment filters

- 6. **Estimate SOM** - 2-5% realistic capture rate

- 7. **Validate** - Cross-check with alternative methods

- 8. **Document** - Show methodology, sources, assumptions

- 9. **Present** - Structure for audience (investors, strategy, operations)