TAM, SAM and SOM as nested boxes, with top-down sizing narro

TAM, SAM and SOM as nested boxes, with top-down sizing narroTAM, SAM and SOM as nested boxes, with top-down sizing narrowing from the outside and bottom-up sizing building from account countsTAM: every buyer with the jobCeiling. Rarely the decision number.SAM: who we can serve nowIntegrations, regions, compliance,channelSOM: what we winReps, partners, win rate,contract value, expansionin a stated periodTop-down:industry total× filtersBottom-up:accounts × valueper account

Top-down sizing narrows an industry total with percentages; bottom-up sizing builds from counted accounts and realistic value per account. Use bottom-up for the decision and top-down as the check. SOM is set by go-to-market capacity, not by a share of TAM.