TAM, SAM, SOM
A framework sizing a market: Total Addressable, Serviceable Addressable and Serviceable Obtainable Market.
TAM is the total demand if you captured everyone; SAM is the portion your model can serve; SOM is the realistic share you can win near-term. Investors use this to judge whether the opportunity is big enough and whether your targets are credible.
Examples
TAM £10bn, SAM £1bn, SOM £20m over three years. — A founder narrows a huge TAM into a focused SOM.
How it relates to The Startup Foundry
Market sizing is central to the Market pillar of the Investability Report — the Foundry helps you size and justify it credibly.