Startup Business Analyst

Chapter 165 of 180

Market Sizing Analysis

Calculate TAM/SAM/SOM for market opportunities using top-down, bottom-up, and value theory methodologies.

1 minute · 269 words · 5 sections

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.

Install this repository

$ npx skills add wshobson/agents

» /plugin marketplace add wshobson/agents

Skills install per repository, not per chapter — the CLI has no documented per-skill form, so we do not print one.

About this skill

Trigger

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.

The verbatim description from this skill’s front matter — the string an agent matches on to decide whether to load it.

Colophon for this issue

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How this issue was made

Source

github.com/wshobson/agents, branch main, last pushed 5 August 2026.

Licence

MIT — the text of every chapter is reproduced unmodified, frontmatter included, under the upstream licence.

Discovery

180 chapters found by walking the repository tree for SKILL.md, not by matching a directory convention. 49 distinct layouts observed: plugins/accessibility-compliance/skills/*/SKILL.md, plugins/agent-teams/skills/*/SKILL.md, plugins/api-scaffolding/skills/*/SKILL.md, plugins/backend-development/skills/*/SKILL.md, plugins/before-you-build/skills/*/SKILL.md, plugins/block-no-verify/skills/*/SKILL.md, plugins/blockchain-web3/skills/*/SKILL.md, plugins/brand-landingpage/skills/*/SKILL.md, plugins/business-analytics/skills/*/SKILL.md, plugins/cicd-automation/skills/*/SKILL.md, plugins/cloud-infrastructure/skills/*/SKILL.md, plugins/conductor/skills/*/SKILL.md, plugins/data-engineering/skills/*/SKILL.md, plugins/database-design/skills/*/SKILL.md, plugins/developer-essentials/skills/*/SKILL.md, plugins/dgx-spark-ops/skills/*/SKILL.md, plugins/documentation-generation/skills/*/SKILL.md, plugins/documentation-standards/skills/*/SKILL.md, plugins/dotnet-contribution/skills/*/SKILL.md, plugins/file-conversion/skills/*/SKILL.md, plugins/framework-migration/skills/*/SKILL.md, plugins/frontend-mobile-development/skills/*/SKILL.md, plugins/game-development/skills/*/SKILL.md, plugins/hermes-tweet/skills/*/SKILL.md, plugins/hr-legal-compliance/skills/*/SKILL.md, plugins/incident-response/skills/*/SKILL.md, plugins/javascript-typescript/skills/*/SKILL.md, plugins/kubernetes-operations/skills/*/SKILL.md, plugins/llm-application-dev/skills/*/SKILL.md, plugins/llm-finetuning/skills/*/SKILL.md, plugins/machine-learning-ops/skills/*/SKILL.md, plugins/observability-monitoring/skills/*/SKILL.md, plugins/payment-processing/skills/*/SKILL.md, plugins/plugin-eval/skills/*/SKILL.md, plugins/pptx-deck-creation/skills/*/SKILL.md, plugins/protect-mcp/skills/*/SKILL.md, plugins/python-development/skills/*/SKILL.md, plugins/quantitative-trading/skills/*/SKILL.md, plugins/reverse-engineering/skills/*/SKILL.md, plugins/review-agent-governance/skills/*/SKILL.md, plugins/security-scanning/skills/*/SKILL.md, plugins/shell-scripting/skills/*/SKILL.md, plugins/ship-mate/skills/*/SKILL.md, plugins/signed-audit-trails/skills/*/SKILL.md, plugins/skill-forge-essentials/skills/*/SKILL.md, plugins/social-publishing/skills/*/SKILL.md, plugins/startup-business-analyst/skills/*/SKILL.md, plugins/systems-programming/skills/*/SKILL.md, plugins/ui-design/skills/*/SKILL.md.

Issue colours

Resolved from a deterministic hash of the owner name. Two accent tones are generated per issue and each is proven against its own ground before it ships: a single accent that passes AA on both light and dark paper is arithmetically impossible.

Heading repairs

1 repair applied to this chapter so the document has one h1 and no skipped levels:

Removed “Market Sizing Analysis”, a leading h1 that duplicated the chapter title.

Spec compliance

1 editorial note across 1 of 180 chapters. They are printed in the margin of each chapter rather than as errors here.

PostgreSQL Table Design — 1 note

Images

Images inside a chapter come from the upstream repository. Where the author gave no alternative text we mark the image decorative rather than inventing a description — a plausible caption we made up is worse than none for the reader who depends on it.

Marketplace

A plugin manifest is published at .claude-plugin/marketplace.json by Seth Hobson, declaring 95 plugins. It is read for editorial metadata only — never as the skill index, which is always the repository tree.

Signal

Install counts come from skills.sh. They measure downloads, not quality, and an unranked repository is not an unread one.

Agent surfaces

The whole issue is available as one markdown document at /wshobson/agents.md, and each chapter at its own .md URL.

Publication

Set by Skills Docs from the source repository. Body text is Literata at the reader’s chosen size and measure; code is Geist Mono. Nothing on this page was written by us except this paragraph.

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

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.

Market Sizing Analysis

Overview

Core Concepts

The Three-Tier Market Framework

When to Use Each Methodology

Detailed patterns and worked examples

About this skill

Trigger

Colophon

Market Sizing Analysis

Overview

Core Concepts

The Three-Tier Market Framework

When to Use Each Methodology

Detailed patterns and worked examples

Appendix 165.1–165.3

ReferencesMarkdown · 2 files

Also bundledMarkdown · 1 file

About this skill

Trigger

Colophon

Appendix 165.1–165.3

ReferencesMarkdown · 2 files

Also bundledMarkdown · 1 file