04/21/2026
There is a number that appears in nearly every investment thesis, growth plan, and board presentation: the total addressable market. It is also, in a significant share of cases, wrong...
It is cited with confidence, displayed in slides, and used to justify headcount decisions, acquisition multiples, and capital allocation.
When it's wrong, it's not just wrong in a minor, rounding-error way. It's wrong in a way that sends a company chasing a market that doesn’t exist at the scale assumed or worse, ignoring a market opportunity that is far larger than their current definition allows.
The consequences are real: capital misallocated, growth theses that fail on contact with actual customers, and deals that look considerably less attractive 18 months post-close than they did in the data room.
The problem isn’t that companies lack a market size estimate. It’s that most have exactly one: a single number, from a single source, validated by nothing but the authority of whoever published the research report.
That is not a TAM. That is a placeholder dressed up as a fact.
CONTINUE READING below to learn how Martec Partner Ken Donaven and Senior Project Manager Tatyanna Dadabbo answer a fundamental but critical question:
👉 "What separates a market size you can defend from one you just cite?"
The problem isn't that companies lack a market size estimate. It's that most have exactly one — a single number, from a single source, validated by nothing but the authority of whoever published the research report. That is not a TAM. That is a placeholder dressed up as a fact.