Blog · GTM
May 10, 2025 · 4 min read
TAM, SAM, and SOM are typically slide content — numbers that live in pitch decks and strategy documents. They rarely inform the day-to-day decisions of an outbound team. They should. Understanding the size and shape of your addressable market changes how you prioritise, how you pace, and how you think about the long-term value of different segments.
TAM (Total Addressable Market) is everyone who could theoretically buy. SAM (Serviceable Addressable Market) is everyone you could realistically reach. SOM (Serviceable Obtainable Market) is everyone you can realistically win in a given period. For outbound planning, SOM is the number that matters.
Start with your ICP and count how many companies fit it. For most industrial or engineering-focused companies, this number is smaller than expected — which is fine. A SOM of 3,000 target companies is a rich outbound universe for a team of two people. A SOM of 500 requires different tactics than a SOM of 50,000.
Within that count, apply a realistic win-rate assumption. If you historically close one in twelve qualified meetings, and you can generate fifteen meetings per month, you will close roughly one new customer per month from this segment. That tells you whether the segment is worth the investment — and how long before you exhaust it.
A small SOM — fewer than 1,000 companies — means you cannot afford to burn contacts. Every prospect is more valuable and re-outreach cycles are shorter. Your sequences need to be higher quality and your exclusion criteria need to be tighter. You cannot blast and hope when you have a limited pond.
A large SOM gives you room to iterate. You can test different segments, different messages, and different timing without worrying that you are burning through your only source of pipeline. Most B2B niches are smaller than they feel — but honest market sizing tells you where you actually stand.