TAM (Total Addressable Market)
Definition
TAM is the total revenue opportunity if you captured 100% of your target market. Used to estimate market size for investors.
Extended Definition
TAM = Total Addressable Market. It answers: how big could this get? Example: if 10M companies need project management software and average contract is $5k/year, TAM is $50B. TAM > SAM > SOM. SAM (Serviceable Available Market) = portion you can reach. SOM (Serviceable Obtainable Market) = what you can realistically capture. Investors want TAM over $1B for VC-scale returns.