TAM / SAM
Total Addressable Market · Serviceable Addressable Market
The size of the market the company is targeting — TAM is the total potential, SAM is the reachable portion.
What it is
TAM (Total Addressable Market): The total market opportunity — how much money the market as a whole spends annually on products or services in a given category. The theoretical maximum revenue ceiling if the company had 100% market share.
SAM (Serviceable Addressable Market): The portion of TAM the company realistically targets with its product, geography, and pricing.
SOM (Serviceable Obtainable Market): Realistically achievable market share in the near term based on the competitive environment and company resources.
Cloud computing example:
- →TAM = total corporate IT spending globally ($4–5T)
- →SAM = cloud infrastructure and platforms (~$1T)
- →SOM = Azure's realistic market share (~$250–300B)
Why track it
TAM/SAM determines how large the company can ultimately grow. Large TAM + low penetration = long growth runway. Small TAM = company quickly hits a ceiling.
Beware of inflated TAM estimates in management presentations — companies always present the maximalist TAM including segments where they don't actually compete. Analyze SAM and actual penetration, not TAM.
Real-world example
Microsoft (from MSFT analysis):
- →Cloud infrastructure TAM: ~$1T
- →SAM (enterprise cloud + AI): ~$300B
- →Current Azure revenue: ~$100B → SAM penetration ~33%
33% SAM penetration means Azure still has significant room to grow even without acquiring new types of customers.
Watch out for
TAM is a lagging metric — the market evolves. A disruptive company can create a new market (expand TAM), while an outdated company sees its TAM shrink. Always monitor whether TAM is growing or contracting.