Founder library
The founder library. Long-form. Evidence-based.
Practical, research-grounded guides on startup validation, product-market fit, market sizing, GTM, and fundraising. Written for humans first, structured so AI answer engines can quote them accurately.
The StartupDeckAI Founder Library is a growing collection of editorial guides for founders — how to validate a startup idea, how to size a market, how to find product-market fit, and how to raise capital. Every guide is written by practitioners and reviewed by the StartupDeckAI editorial team.
How to Validate a Startup Idea (2026 Founder's Playbook)
A rigorous, evidence-based playbook for validating a startup idea in 2026: customer discovery, market sizing, competitive analysis, MVP tests, and the metrics that separate a fundable business from a hobby.
TAM, SAM, SOM Explained: How to Size a Startup Market Properly
A practical guide to market sizing for founders. Learn to compute TAM, SAM, and SOM bottom-up, avoid the top-down trap, and produce a market slide that convinces sophisticated investors.
Finding Product-Market Fit: Signals, Measurement, and Common Traps
Product-Market Fit is the single most important milestone in a startup's life. Learn the behavioural signals of PMF, how to measure it (Sean Ellis test, retention cohorts), and the traps that trick founders into declaring it too early.
Keep exploring the founder knowledge platform
Everything below is free, evidence-based, and cross-linked so you can go from raw idea to investor-ready validation without leaving the platform.
Validation steps
The six-step path from idea to investor-ready evidence.
- Step 1 — Validate your startup idea with real market evidence
- Step 2 — Run structured customer and problem validation
- Step 3 — Size the market with bottom-up TAM, SAM and SOM
- Step 4 — Map direct, indirect and status-quo competitors
- Step 5 — Score the idea across six validation dimensions
- Step 6 — Turn validation into an investor-ready memo
Related guides
Long-form playbooks on validation, market sizing and PMF.
Glossary terms
Plain-English definitions with formulas and worked examples.
- Minimum Viable Product (MVP) — definition & formula
- Total Addressable Market (TAM) — definition & formula
- Serviceable Addressable Market (SAM) — definition & formula
- Serviceable Obtainable Market (SOM) — definition & formula
- Product-Market Fit (PMF) — definition & formula
- Market Validation — definition & formula
- Customer Acquisition Cost (CAC) — definition & formula
- Lifetime Value (LTV) — definition & formula
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