The book lists nineteen distinct ways of getting customers — from advertising and search to trade shows, events, partnerships, affiliate programmes or building a free tool as a form of marketing — and proposes a method for choosing: consider all of them, keep a few promising ones, test them cheaply, then concentrate on whichever works.
What I took from it
The step that looks bureaucratic and does the actual work: forcing yourself through the whole list. Most people consider two or three channels, the ones they already know or the ones their competitors use, and discard the rest without looking. Walking all nineteen takes an hour, and two you had not thought of always surface.
The discipline of testing cheaply before committing. The test question is not whether it works but what one customer costs through that route, and that figure can be estimated with very little money. What cannot be done is deciding on instinct and finding out three months later.
And the rule of splitting time between building the product and getting customers in comparable halves. Written down it looks excessive, until you check where the month went.
What I left out
The per-channel chapters, which are condensed interviews and teach you to execute nothing. Anyone wanting to run search ads or email needs a dedicated book; these chapters are enough to decide whether to look, not to do. And the book is written for startups chasing fast growth with investment behind them: someone working alone has to discard the channels that require a team up front, and that cuts the list by more than half.