Glossary

What is total addressable market (TAM)?

Total addressable market, or TAM, is the total revenue available for a product if every possible customer bought it. Serviceable addressable market, SAM, is the part you can actually reach with your product and channels. Serviceable obtainable market, SOM, is the share you can realistically win soon. For outbound, the useful number is a count of real accounts.

Published by Sellinger AI. Numbers and settings checked on 24 October 2026 against the fact register. Report an error.

How do TAM, SAM and SOM differ?

Three layers of market size
Layer	Question	Example (illustrative)
TAM	Everyone who could buy this, anywhere	All logistics companies with 50 to 500 staff worldwide
SAM	The part you can serve today	Those in the countries and languages you sell in
SOM	The part you can win in the next year or two	The share your team can reach and close

How do you size it bottom up?

Count accounts, then multiply. An example with made up numbers: 3,000 companies match your profile in your countries, about a third have the problem you solve, and your average deal is 10,000 a year. SAM is about 1,000 x 10,000 = 10,000,000 a year. Bottom up sizing is more useful than top down industry reports, because it gives you a list you can actually work.

Why does TAM matter for outbound?

Because a small market runs out. A team that writes to 500 people a month in a market of 2,000 accounts will exhaust it within a year, and every follow up and re-engagement matters more. In the Lamothermic campaign, volume fell after July because the lead list ran out, not because the agent slowed down.

How Sellinger handles it

Searching people and companies over a database of 700M+ contacts gives a quick bottom up count of the accounts and people that match your filters. Sellinger does not produce market size estimates.

Common questions

Should a startup report TAM to investors?

Investors often ask for it. A bottom up number with a clear method is more credible than a large top down figure.

Is a big TAM always good?

Not for outbound. A clearly defined smaller market with a real need is easier to work than a vague large one.

What is the difference between SAM and SOM?

SAM is what you could serve. SOM is what you can realistically win soon.

Sources and method

General market sizing practice; examples are illustrative. Lamothermic from its case study. Sellinger data from the fact register, checked 24 October 2026.