Do · test a business

Test a business idea for almost nothing

Updated 2026-07-25 · Sources: 14

The cheapest way to find out whether an idea works is not to build it. It is to ask Mom-Test-style questions about past behavior, presell before you make anything, smoke-test with a one-page offer, or run a $100 pilot in a market you already belong to. Jesus put the principle in a builder's mouth: which of you, intending to build a tower, "sitteth not down first, and counteth the cost" (Luke 14:28, KJV)? Cheap testing is cost-counting made practical.

Serve first: the ethic behind every test

Profit is the byproduct of service, not the other way around. Jesus described even his own mission as coming to serve rather than to be served (Mark 10:45, paraphrased), and a business only deserves to exist if it serves someone well. Honest margins are honest scales: a just weight delights God, a false balance does not (Proverbs 11:1; Leviticus 19:36).

• Make something people want

  Y Combinator's motto and the core of Paul Graham's essays. The standard failure mode is building what nobody asked for: a business that survives only by serving customers well is, structurally, loving your neighbor with a product (Matthew 22:39, applied).

  Paul Graham: How to Make Wealth · YC Startup School (free)

• Every business is five parts

  Josh Kaufman's Personal MBA framework: value creation, marketing, sales, value delivery, finance. If one is missing, it is a hobby, not a business.

  The Personal MBA

Ask about their life, not your idea: the Mom Test

Rob Fitzpatrick's rule: never ask "is my idea good?" Everyone, especially your mom, lies politely. Three rules replace the question.

• Rule 1: talk about their life, not your idea

  Ask what they do today, what it costs them, what they have already tried. Your idea never enters the conversation.

• Rule 2: ask about specifics in the past, not hypotheticals

  "How do you handle X today? What does it cost you?" beats "would you use this?" every time. People are honest about what they did; they are polite about what they might do.

• Rule 3: talk less, listen more

  Listening rather than pitching is also the humbler posture: let another praise you (Proverbs 27:2), and be quick to hear (James 1:19).

momtestbook.com · Sachin Rekhi's summary · mtlynch.io book report

Sell it before you build it

• Presell: the strongest signal

  Take real money, or signed commitments, before building anything. If nobody pre-pays, the polite compliments were lies. This is the core method of Chris Guillebeau's The $100 Startup: launch tiny, invest about $100, sell first, refine with real customers.

  The $100 Startup · Summary (Readingraphics)

• Landing-page smoke test

  One page describing the offer plus a "buy" or "join waitlist" button; drive a little traffic; measure clicks and signups before the product exists. The famous examples in The Lean Startup (Dropbox's demo video, Zappos buying shoes retail only after an order came in) are as recounted in the book; we have not independently re-verified them.

• Concierge first, MVP second

  Deliver the service completely by hand to three to five customers before automating anything. You learn what they actually value. Then ship the smallest thing that tests the riskiest assumption, measure real behavior, and iterate or kill. Recruiting those first customers personally, door to door if needed, is Paul Graham's "do things that don't scale."

  Paul Graham: Do Things That Don't Scale · Inc. summary · YC Startup School

• The $100 discipline

  Cap the experiment budget and set a pass/fail number in advance, "10 preorders in 2 weeks or we stop", so the test can actually fail. A capped test is stewardship of limited resources: faithfulness in little (Luke 16:10), without presuming on next year's profits (James 4:13-15).

Run it like a steward: the numbers

• Cash flow beats profit on paper

  Even a busy business dies if payment arrives in 90 to 180 days unplanned. Project cash flow, invoice fast, keep reserves.

  SCORE: ten tips for new small businesses · SBA Financial Management Workbook (via SCORE) · U.S. Bank: managing cash flow

• Know your margin and break-even

  Contribution margin, price minus variable cost per unit, sets your break-even and your pricing floor. Price on the value delivered, not cost-plus timidity. Knowing your numbers is old counsel: Proverbs 27:23 tells the shepherd to know well the condition of his flocks.

  U.S. Bank: managing cash flow

• Use the free help

  SCORE offers free volunteer mentors nationwide as an SBA resource partner, and the SBA publishes free courses and financial-literacy resources. Free, experienced counsel is rare. Take it.

  SCORE: plan and start · SBA: manage your business finances (Business Guide)

• One channel, done well

  Find where your customer already is; one marketing channel done well beats five done badly; and ask every customer where they heard of you.

Training wheels: pilots for kids and teens at school and church

School, neighborhood, and church are ideal first test markets: known customers, low cost, fast feedback. A kid can Mom-Test the neighbors ("what yard job did you pay for last?"), presell ten cookie boxes before baking a single one, or pilot a Saturday car wash at church with a signup sheet as the landing page. It is the same lean loop at training-wheels scale.