β Glossary
TAM / SAM / SOM
Three nested measures of market size: Total Addressable Market, Serviceable Addressable Market, and Serviceable Obtainable Market.
TAM is the total revenue opportunity if you captured 100% of the market β useful for context but unrealistic. SAM narrows it to the segment you can actually serve with your current product and go-to-market strategy. SOM is the realistic portion of SAM you can capture in the near term, typically 1-5% for a new entrant. Investors care about TAM for ceiling potential but evaluate your plan based on SOM. A common mistake: using TAM in pitches as if it's achievable revenue.