What&#x27;s badly needed here is a sensitivity analysis.<p>For example, he lists ZocDoc&#x27;s CAC as in the range $1k to $10k.<p>If it&#x27;s $1k then their LTV&#x2F;CAC = 4.8 (wow good!)<p>If it&#x27;s $10k then their LTV&#x2F;CAC = 0.48 (wow horrid!)<p>The author chose $3k, seemingly arbitrarily.<p>There&#x27;s nothing wrong with arbitrary assumptions in general, but in this case a lot more scrutiny is needed before we judge if its a unicorn or donkey.