---
title: ICP, Segmentation, and TAM — RGM Training
url: https://realgrowthmatters.com/training/b2b-saas-growth/icp-segmentation-and-tam/
updated: 2026-06-10
source_html: https://realgrowthmatters.com/training/b2b-saas-growth/icp-segmentation-and-tam/
---

[Home](../../../index.html) › [Training](../../index.html) › [B2B SaaS Growth](../index.html) › ICP, Segmentation, and TAM

RGM° · Training

# ICP, Segmentation, and TAM

Strategic foundation. TAM/SAM/SOM, ICP layering, segmentation, personas, buying committee, research methods.

### What you will learn

1. [Why ICP segmentation is the strategic foundation](#why)
2. [TAM, SAM, SOM](#tam)
3. [ICP layering](#icp)
4. [Segmentation in B2B SaaS](#segmentation)
5. [Personas and buying committee](#personas)
6. [Research methods](#research)
7. [Advanced playbook](#advanced)
8. [Common mistakes](#mistakes)
9. [Checklist](#checklist)

## Why this matters

Without rigorous ICP and segmentation, B2B SaaS growth chases the wrong audiences with the wrong messages. The mistake: defining ICP too broadly. The discipline: niching down enough to be the obvious choice for a specific segment, then expanding from strength.

## TAM, SAM, SOM

- **TAM (Total Addressable Market):** Total revenue if you owned 100% of the market.
- **SAM (Serviceable Addressable Market):** The portion your product can actually serve.
- **SOM (Serviceable Obtainable Market):** The portion you can realistically capture given competition, GTM, etc.
- **Bottom-up:** Companies in segment × ACV. More credible than top-down.
- **Top-down:** Industry size × market share. Useful but often overstated.

## ICP layering

- Firmographic (industry, size, geography, business model).
- Technographic (tech stack, complementary tools).
- Behavioral (buying patterns, growth stage).
- Pain alignment (problems your product solves).
- Value alignment (willingness to pay).
- Distribution access (reachable through channels).

## Segmentation

- By company size (SMB, mid-market, enterprise).
- By industry vertical.
- By use case.
- By geography.
- By tech maturity.
- By buyer (champion vs decision-maker vs user).

## Personas and buying committee

- **Champion:** Internal advocate who'll push the deal.
- **Decision-maker:** Has final authority.
- **User:** Day-to-day operator.
- **Influencer:** Affects decision but doesn't own it.
- **Blocker:** Could derail (IT, security, legal, finance).
- Each persona needs targeted content and outreach.

## Research

- Customer interviews (10–30 minimum).
- Win/loss analysis quarterly.
- Sales call recordings.
- Customer success conversations.
- Sales-team workshops.
- External research (Gartner, Forrester, peer firms).

## Advanced playbook

- Tiered ICP with explicit exclusion criteria.
- Annual ICP refresh based on customer data.
- Cohort LTV by segment.
- Win rate by segment.
- Sales playbook per segment.
- Persona-specific content libraries.
- ABM tier strategy aligned with ICP tiers.
- Quarterly review of ICP performance.
- Anti-ICP documented (who NOT to sell to).
- ICP-aligned compensation.

## Common mistakes

- ICP too broad; no defensibility.
- Persona work shallow; demographics only.
- Buying committee unmapped.
- Anti-ICP not documented.
- Sales chasing non-ICP for short-term revenue.
- Marketing speaking to wrong personas.
- Cohort LTV by segment not tracked.
- Win rate by segment not analyzed.
- ICP not refreshed annually.
- External validation skipped.

## Operating checklist

- Documented ICP with firmographic + behavioral criteria
- Anti-ICP / exclusion criteria explicit
- Buying committee personas mapped
- Annual ICP refresh
- Win rate by segment
- LTV by segment
- Sales playbook per segment
- Persona-specific content
- External validation
- ICP discipline in pipeline review

## Sources and further reading

- Bob Moesta JTBD methodology
- Forrester / SiriusDecisions B2B ICP frameworks
- April Dunford positioning
- Tomasz Tunguz segmentation research
- Andrew Chen ICP essays
- HubSpot ICP playbooks
- Demand Gen Report research
- RGM ABM Mastery ICP module
- Mark Roberge sales segmentation
- Drift, Gong B2B research
- Refine Labs ICP framework
- Reforge B2B curriculum

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Part of the [B2B SaaS Growth](../index.html) series.