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

Detailed patterns and worked examples

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