Everyone focuses on the Total Addressable Market (TAM), which gives an unrealistic expectation of your market size.
Instead SOM gives you a more practical estimate.

14 mental models that helped me build 10 startups and sell (a bunch of them) for millions.
— Joe Speiser \u26a1\ufe0f (@jspeiser) October 24, 2022
1/ What is \u201cproduct/market fit\u201d? I\u2019m not sure I can give you a definition. But maybe I can share what the subjective difference is in how it feels when you have it and when you don\u2019t. Founding a startup is deciding to take on the burden of Sisyphus: pushing a boulder up a hill.
— Emmett Shear (@eshear) July 27, 2019