GTM Glossary · Market Entry
Serviceable Obtainable Market (SOM)
The realistic share of the serviceable market you can win in a defined period with the team, budget, and time you actually have.
[01]What It Means
SOM is TAM after constraints and competition, divided by what your capacity allows in the planning window. It is the only market figure that belongs in an operating plan, because it is the one you can be held to.
[02]Why It Matters
Entry plans fail on sequence more often than on ambition, and SOM is where sequence becomes explicit: which segment first, with how many sellers, over how many quarters. It converts a market story into a hiring and spend decision.
[03]Where It Goes Wrong
Deriving SOM as a fixed percentage of TAM rather than from capacity and cycle length.Planning SOM without sales-cycle reality, so revenue is booked in a quarter the pipeline cannot reach.Setting SOM before validating the ICP, which makes every downstream number a guess.
[04]Related Terms