Video · 5 min

Bill Gurley on Why Founders and Investors Should Not Pay Too Much Attention to TAM

Bill Gurley · Startup Archive Free Intermediate

A short clip where Gurley explains why top-down TAM estimates are often badly wrong, using Uber and the early cell phone market as examples. It is useful ammunition when an investor over-indexes on your top-down slide. Watch it to see why the number that frames ambition should never be the number you stake your credibility on.

  • Historical top-down market data badly underestimates category creators
  • The top-down number frames ambition but is easily wrong
  • Defend the parts of your case that hold up under scrutiny
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The question it answers

  1. Investors keep asking for a top-down TAM slide, but I built my number bottoms-up. Which do I show?

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