The Terrifying Art of Finding Customers (Book Summary)

Early revenue isn’t proof of product-market fit. It’s often a mirage.

Collin Stewart’s The Terrifying Art of Finding Customers lays it bare: without pull, every dollar spent on GTM is a tax.

This post distills his playbook into one core principle, tighten the fit before you scale, and shows how to turn signal-rich interviews into real demand, referrals, and compounding growth.

PMF Before Pipeline

“Too many founders mistake early revenue for PMF and scale before they’re ready.” That’s the opening punch of Collin Stewart’s new book, and the heartbeat of this summary. If growth feels random, this isn’t about hustle; it’s about fit. Strengthen product-market fit (PMF) first, then build a revenue engine that actually compounds.

“PMF isn’t yes/no. It’s a spectrum.”

This post distills the book into a concise playbook: how to identify genuine demand, convert interviews into customers, and know when to scale, without burning through cash.

The Core Idea: Fit First, Then Scale

Great markets pull product out of you. A weak fit punishes every dollar you invest in GTM. That’s why PMF isn’t binary. On one end, prospects ignore your emails, interviews stall, and referrals are flat. On the other hand, customers lean in, introducing you to peers, forgiving bugs, and asking for more.

The point isn’t to “do sales harder.” It’s to earn pull before you add fuel. When pull shows up, the same outreach, budget, and team suddenly perform better: higher reply rates, faster closes, lower churn. Until then, more activity just increases noise.

“The market will be fulfilled by the first viable product that comes along.”

Your job is to become that product by tightening the fit, then scaling the machine.

How to Find Real Demand

Most teams pitch too soon. Collin’s path is a four-stage customer-development funnel that keeps you in learning mode until the market proves it’s ready to buy.

Exploratory interviews. Speak with 10–20 individuals in your target market. No demo. No pitch. Ask about the last time the problem hurt, what they tried, why it failed, and what “done” looks like. You’re collecting language and constraints.
Focused interviews. Now, bring a point of view. “I’m exploring X for Y, am I off?” Pressure-test problem boundaries, stakeholders, and success criteria to ensure alignment. You’re aiming for sharper patterns, not a close.
Paper feedback. A one-pager with the problem, proposed outcome, and a simple “how.” No code. Ask: “What’s wrong? What’s missing? Would you pay for this? Why or why not?” If nobody argues with the paper, nobody will fight for the product.
MVP demo. Show the smallest thing that proves the outcome. The Wizard of Oz is fine (manual behind the scenes). Then shut up and watch. Do they ask for a trial? Do they introduce you to someone else? Do they want to pay?

Through all four stages, bias toward 98% learning / 2% pitching. You’re not closing; you’re validating. When the switch flips, you’ll feel it: people will start pulling the solution out of you.

Your First Customers (and Referrals)

Interviews should convert into early buyers. If they don’t, something’s off: ICP, problem gravity, or the offer. The strongest PMF signal isn’t a single sale; it’s momentum.

At Carb.io, a scrappy, Wizard-of-Oz MVP with manual behind-the-scenes work produced real outcomes fast.

Customers didn’t just buy. They referred to peers. Intros began to “flood in.” That’s pull. On the other hand, when teams scale prematurely (by increasing paid spend, hiring more SDRs, and expanding SKUs), those organic referrals tend to dry up. That’s a red flag. Don’t “double down.” Step back and fix the fit.

Your litmus test: after a handful of deployments, do customers (a) achieve the promised outcome, (b) recommend you unprompted, and (c) ask for adjacent value? If not, you’re forcing it. Tighten the niche, simplify the promise, and return to interviews.

Getting Ready for Growth

When fit strengthens, use the growth formula to decide how hard to push:

Growth = Cash × PMF × Revenue Execution (later × Power).

Cash funds, experiments, and time-to-learn.
PMF multiplies everything. A stronger fit makes the same playbook hit harder.
Revenue Execution is your GTM: messaging, channels, ops.
Power (later): durable advantages, such as network effects or brand.

The move isn’t “hire a dozen SDRs.” It’s to fix the weakest lever first. If the PMF is shaky, no amount of execution can offset it. If cash is tight, pace experiments. If execution lags, sharpen ICP, upgrade messaging, and clean handoffs. Growth occurs when all three core levers are aligned in the same direction.

Building the Machine

Once fit improves, build a system that turns interest into revenue without founder heroics. Split your motion into four simple funnels so problems are obvious and fixable:

Meet. How you get in front of ICP: referrals, communities, cold, and content. Measure quality, not just quantity.
Discovery. How you learn and diagnose: questions, proof, and a clear success plan. Lose fast when it’s a misfit.
Manage. How do you onboard and deliver the minimum delightful outcome quickly and reliably? Early wins buy trust.
Nurture. How you maintain momentum: QBRs, success milestones, and expansion triggers. Make the next step obvious.

Separating these funnels speeds learning. If reply rates are healthy but the first value is late, the issue is in Manage, not Meet. If QBRs don’t lead to expansions, the issue is in Nurture, not the pipeline. Fix the right link, and the chain strengthens.

Founder-Led Sales to $1M

Early on, the founder must own sales. Not forever, but long enough to preserve signal fidelity. You need to hear objections, watch prospects’ faces when you show the MVP, and update the product and promises on a weekly basis. That loop dies when you outsource too early.

Founder-led doesn’t mean “do it all.” It means you run discovery, approve messaging, and sit in key calls while a small team handles research, scheduling, and ops. As PMF tightens and patterns stabilize, address common objections, ensure repeatable onboarding, deliver consistent outcomes, and document the playbook. Only then hire for replication, not invention.

Conclusion

Scaling before fit is like pouring fuel on wet wood, wasteful and frustrating.

Instead, build signal loops, validate through real customer pull, and earn the right to scale. PMF isn’t a finish line; it’s a multiplier. When it clicks, growth accelerates with the same inputs. Until then, your job isn’t to grow. It’s to learn, refine, and tighten the fit.