The Most Expensive Startup Mistake Happens Before You Write a Single Line of Code
When things go south, it's probably not a product problem; it's a learning problem.
Article Summary
Most founders think startups fail because they build the wrong product. Others blame weak marketing, poor execution, or running out of money. Those certainly happen, but they often distract attention from a much earlier decision that affected everything that followed.
Long before you write your first line of code, sketch your first screen, or ask AI to generate your MVP, you must decide who exactly you’re creating your product for. That decision determines how quickly you learn, how clearly you position your product, how confidently customers respond, and ultimately how quickly your product becomes a success and captures its market.
The Real Startup Mistake Happens Before the Product Exits
During the first startup accelerator I mentored back in 2013, every founder was asked the same question during the opening reception.
“What can the mentors here help you with?”
I thought I already knew the answers.
Some founders would ask about raising capital. Others would want introductions to potential customers. A few would ask for advice on hiring, pricing, or refining their pitch.
Those were the problems I expected to hear about, because they were the issues founders discussed most often.
Instead, something unexpected happened.
The Accelerator Question That Exposed the Problem
Founder after founder asked essentially the same question.
“Which market should we be targeting?”
At first, that question sounded perfectly reasonable. Choosing the right customer is difficult.
Then, after having the opportunity to talk with many of the founders in attendance, something completely changed the way I think about startups.
Most of these companies had already started building.
Some had prototypes. Others had working software. A few had already invested months of design and engineering efforts and had spent significant amounts of money. They had product roadmaps, feature lists, development schedules, and launch plans.
What they didn’t have was a clear answer to one deceptively simple question.
Who exactly is our product for?
That realization has stayed with me to this day, because it exposed a pattern I would see again and again.
Building Before Choosing a Target Customer Creates False Momentum
Founders weren’t struggling because they lacked technical ability or ambition. They were struggling because they had decided what to build before deciding who they were building it for.
At first glance, that doesn’t sound like a serious mistake. After all, if you have a good idea, why not start building and figure out the customer along the way?
The answer is that startups don’t learn from building; they learn from customers.
Building simply turns your assumptions into something customers can react to.
If those assumptions are aimed at the wrong customer, every hour spent building takes you farther down the wrong path.
AI Has Made Speed Less Valuable Than Judgment
That distinction has become even more important over the past two years.
Not because startups have changed.
Because building has changed.
Ten years ago, creating a software product required months of design and development effort. Today, AI can generate working applications, marketing copy, landing pages, and onboarding flows in a matter of hours. Founders can and do build faster than ever before.
That sounds like an enormous advantage, and in many ways, it is.
But when something becomes easier, we naturally spend more time doing it.
Today’s founders can make visible progress every day. The interface improves, new features appear, and bugs are addressed. The product becomes more polished with each iteration.
It feels like momentum, and sometimes it is. But sometimes it’s simply a faster way to build something based on untested assumptions.
AI has removed one bottleneck, but it hasn’t removed the need for judgment.
If anything, judgment has become more critical because it determines where all that time and effort created by development speed gets directed.
Your First Market Determines Everything That Follows
That’s why I believe the most important decision you make isn’t your technology stack, your pricing model, or even your feature roadmap. It’s deciding which target market deserves your attention first.
That one decision influences every subsequent decision.
It determines whose problems you observe and the questions you ask during customer interviews. Those interviews shape the product you build. The product shapes your positioning. Your positioning shapes your messaging. And your messaging attracts your earliest customers.
The customers you interview can influence feature requests, product decisions, and eventually whether you ever build a winning product.
When founders tell me they’re struggling with positioning, I no longer assume they have a messaging problem.
When the product seems overly complicated because it has too many unrelated features, I don’t immediately assume there’s a product functionality problem.
And when sales conversations go in ten different directions, I don’t assume the sales process needs work.
More often than not, all three of these symptoms point back to the same underlying issue. The company is trying to learn from too many different customers at the same time. And that’s where so many startups begin to go sideways.
Startups Learn Slowly When They Listen to Too Many Customers
Startups rarely fail because they build too slowly. They fail because they learn too slowly. And that’s where almost every startup begins to falter.
That may sound surprising.
Most founders don’t wake up one morning and deliberately decide to slow their own learning. In fact, they believe they’re doing exactly the opposite.
They cast a wide net because they want to learn from as many people as possible.
It feels logical.
The larger the market, the more potential customers you can interview, the more interviews you conduct, the more feedback you get, and the more feedback you get, the better your product should become.
At least that’s what best practice preaches.
The flaw in that reasoning isn’t the desire to learn. It’s the assumption that all customer feedback is equally valuable; it isn’t.
Some feedback reveals patterns while some creates confusion.
The difference almost always comes down to who you’re talking to.
Broad Markets Create Confusing Feedback
Imagine you’re trying to understand why emergency rooms become overwhelmed during peak hours. You wouldn’t interview emergency room physicians, medical coders and billers, healthcare compliance officers, and hospital dietitians simply because they’re all hospital professionals. Each conversation might be interesting, but comparing them would tell you very little about emergency room operations.
Instead, you need to interview people working in the same environment, facing the same constraints, and trying to accomplish the same objectives. That’s when meaningful patterns begin to emerge.
Customer discovery works the same way.
The purpose of interviewing customers isn’t to collect opinions. It’s to identify patterns that help you make better decisions, and patterns only emerge when your customers are similar enough that their experiences can be meaningfully compared.
That’s where many founders unintentionally go off course.
They define their market using broad categories that sound precise but really aren’t.
“We’re creating a product to improve emergency room operations.”
That feels specific because it’s narrower than saying “hospitals,” but in reality, it’s still too broad a market.
The challenges facing Paramedics & EMTs who provide life-support during ambulance transport, Care Coordinators who help bridge the gap between the ER and other departments, and Medical Scribes who assist physicians by updating electronic health records are all different.
On paper, these customers belong to the same market: emergency room operations. In practice, they don’t.
Feature Creep Often Starts With the Wrong Customer Conversations
That distinction becomes painfully obvious once customer interviews begin.
Each request comes from a real potential customer, and each request feels difficult to ignore.
The founder leaves those conversations convinced they’ve uncovered a tremendous opportunity.
But what they’ve actually uncovered are several different potential customers.
That misunderstanding creates one of the most expensive forms of waste inside a startup: feature creep. Feature creep isn’t usually caused by poor discipline; it’s often caused by inconsistent learning.
When every potential customer has a different job function with different priorities, every feature request sounds equally important. But the product roadmap slowly becomes a collection of compromises rather than a clear expression of a specific type of customer’s urgent needs.
Positioning Breaks When the Target Market Is Too Broad
When the target market is too broad, the product grows larger, while the value proposition becomes weaker.
Eventually, the team begins asking a familiar question.
“Why isn’t our messaging resonating?”
The answer usually isn’t about better copywriting.
It’s because of the broad market approach that was used during customer interviews and conversations.
Positioning becomes remarkably difficult when you’re trying to describe a product that serves several different types of customers equally well.
Strong positioning doesn’t begin with words; it begins with focus.
A Real Niche Is Defined by a Shared Painful Problem
That’s why I think many founders misunderstand what a niche actually is.
A niche isn’t simply a smaller demographic.
A meaningful niche is a group of customers who share the same costly problem, experience it under similar circumstances, and define success in a similar way.
Notice what’s missing from that definition?: Demographics like “industry”, “company”, “size”, “annual revenue”, etc.
Those characteristics may matter, but they aren’t what make a market coherent.
The coherence comes from the specific problems that potential customers face.
Repetition in Customer Interviews Is a Good Sign
Suppose you’re building software that automates prior authorization requests from insurance companies for independent physical therapy clinics.
You’ve immediately narrowed your market, not because physical therapists are inherently more interesting than anyone else, but because each experiences the same frustrating workflow every day.
They deal with similar insurance requirements, staffing constraints, documentation burdens, and financial consequences when approvals are delayed.
Now imagine interviewing twenty clinic owners.
The conversations won’t be identical; they shouldn’t be.
But you’ll start hearing the same themes over and over.
Documentation takes too long, claims get rejected for preventable reasons, staff members often spend hours following up with insurers, and cash flow suffers because reimbursement is delayed.
Those repetitious stories are incredibly valuable because they reduce uncertainty.
Instead of trying to interpret twenty unrelated opinions, you’re uncovering twenty different perspectives on the same underlying problem.
That’s when customer discovery begins doing what it’s supposed to do.
It starts improving your judgment.
Learning Velocity is the Real Advantage of Narrowing Your Market
One of the most important lessons I learned as a mentor was discovering that the most productive customer interviews sound repetitive.
Founders occasionally worried that hearing the same complaints over and over meant they weren’t talking to enough different people. But repetition isn’t a weakness. It’s evidence that they are talking to people in the same niche target market.
Every recurring complaint increases confidence that the problem is real, every repeated frustration makes product priorities clearer, and every familiar story strengthens the company’s understanding of what customers actually value.
Learning accelerates because the signal becomes stronger while the noise and inconsistencies start to disappear.
That’s why I believe the real advantage of narrowing your first market has very little to do with marketing; it has everything to do with learning velocity.
The faster you recognize patterns, the faster you make better product decisions.
The faster you make better product decisions, the sooner customers begin recognizing that your product feels as though it was built specifically for them.
That isn’t an accident. It’s the natural consequence of spending time listening to people whose working lives resemble one another.
Once you begin thinking this way, something interesting happens.
The companies we usually celebrate for serving enormous markets start looking very different.
Instead of seeing giant businesses, you begin seeing founders who deliberately limited themselves long enough to learn faster than everyone else.
Square Won by Starting With an Overlooked Customer
Square is one of the clearest examples.
When most people think about Square today, they picture a financial technology powerhouse serving millions of merchants around the world. They think about payment terminals, payroll services, banking, lending, inventory management, e-commerce, and dozens of other products that have been added over the years.
That isn’t the company Jack Dorsey and Jim McKelvey set out to build.
Their first insight was surprisingly narrow.
Millions of independent merchants couldn’t accept credit cards, not because the technology didn’t exist, but because the existing solutions were built for someone else.
Traditional payment processors focused on large, established businesses with predictable transaction volumes. Contracts were complicated. Equipment was expensive. Approval processes were slow. For a vendor at a weekend craft market or people working in a food truck, accepting card payments wasn’t worth the cost or hassle.
Square wasn’t competing for the largest market. It was solving a painful problem for people that the rest of the industry had largely ignored.
That decision shaped everything.
The product wasn’t designed to impress enterprise retailers. It was designed to make one frustrating task disappear for one very specific kind of customer. The hardware was simple. Pricing was transparent. Getting started took minutes instead of days. Every part of the experience reflected a deep understanding of the customer’s daily reality.
Communities Communicate. Markets Don’t
What happened next? Those early customers didn’t simply buy the product; they recommended it.
Word spread because people within that community talked to one another. Street artists sold beside other artists. Food truck owners shared experiences with other food truck owners. Independent retailers learned from neighboring retailers.
Referrals aren’t driven by expensive advertising campaigns; they spread because the product solved a problem that many people within the same community experienced every day.
That’s an advantage broad markets rarely provide.
Communities communicate; markets don’t.
The same pattern appears almost every time you look closely at a successful startup.
Growth comes through adjacent markets, not unrelated ones.
PayPal Proved That Sequential Growth Beats Broad Ambition
PayPal followed a remarkably similar path.
The company didn’t begin by trying to transform online commerce. Its earliest traction came from power sellers on eBay, a tightly connected community struggling with the same frustrating payment process. Addressing that one problem exceptionally well created the credibility and momentum needed to expand much further.
Square and PayPal weren’t thinking small.
They were thinking sequentially.
That’s an important distinction.
Your First Market is a Learning Laboratory
Founders sometimes hear advice about narrowing their market and assume they’re being encouraged to lower their ambitions.
Nothing could be further from the truth.
The objective isn’t to build a smaller company; it’s to reduce uncertainty as quickly as possible.
Every startup begins life with a long list of assumptions.
You assume the customer has a particular problem, the problem is painful enough to justify solving, your approach is meaningfully better than existing alternatives, and customers will pay enough to support a viable business.
Those assumptions are unavoidable.
The mistake is trying to test all of them across five different customer groups at the same time.
Learning slows because every conversation introduces new variables.
The founders who reach product-market fit fastest usually eliminate variables instead of adding them.
They ask a simpler question.
“What is the smallest market where my assumptions appear to be true?”
That question changes the purpose of your first market.
Instead of viewing it as the destination, you begin viewing it as your learning laboratory.
Your first market doesn’t have to sustain the company forever.
It needs to teach you faster than any broader market could.
Customer Interviews Should Be Based On Behavior, Not Compliments
That shift in thinking also changes the way you conduct customer interviews.
Many founders approach their initial customer interviews hoping to validate an idea.
They’re looking for enthusiasm.
They want prospects to say, “I’d definitely use that.”
Unfortunately, compliments are easy to collect; evidence is much harder.
The most valuable interviews rarely make you feel more confident.
They make you more informed.
A customer who says, “That’s interesting,” hasn’t told you very much.
A customer who says, “Last month this problem cost us three contracts, and we’ve already tried two different solutions that failed,” has given you something infinitely more valuable.
They’ve given you context, and context explains behavior.
Behavior predicts buying decisions far better than opinions ever will.
That’s why I encourage founders to spend less time discussing hypothetical features and more time exploring what customers are doing today.
How are they solving the problem?
How much time does it take?
What workarounds are they using?
What frustrates them most about the current approach?
What happens if nothing changes?
Motivation Matters More Than Feature Requests
Those questions uncover something far more useful than feature requests.
They uncover motivation.
Motivation is the raw material from which great products are built.
Once you understand what customers are truly trying to accomplish, feature prioritization becomes dramatically easier.
You’re no longer asking, “What should we build next?”
You’re asking, “What removes the greatest amount of friction from the customer’s journey?”
That’s a very different conversation.
It’s also where many founders discover that the feature they were most excited about matters very little to customers. The opposite happens as well.
A capability that seemed almost insignificant turns out to solve the one problem customers care about most.
Those discoveries don’t come from brainstorming.
They come from repeated interactions with the same type of customer struggling with the same job.
Judgment is Becoming the Founder’s Most Valuable Advantage
That’s why I often tell founders that customer interviews aren’t primarily about validating ideas or getting feedback on MVPs; they’re about improving judgment.
And judgment is becoming one of the most valuable competitive advantages in the age of AI.
Today, almost anyone can build software; far fewer people know where to direct that effort.
The bottleneck has shifted.
Technology is no longer the scarcest resource.
Good decisions are.
The founders who consistently outperform their competitors aren’t necessarily the fastest builders; they’re the fastest learners.
And learning speed begins with one deceptively simple decision.
Choosing the right first customer.
The Best First Market is Not Always the Largest Market
That brings us back to the question those founders asked during the accelerator more than a decade ago.
“Which market should we target?”
At the time, I thought they were asking a marketing question; now I understand that they were asking the most important product question they would ever face.
Total Addressable Market (TAM) Matters Later Than Founders Think
The answer wasn’t in an estimate of the TAM. It wasn’t buried inside demographic reports or industry forecasts. Those sources have value, especially when you’re raising capital, but they rarely tell you where your startup should begin.
Investors certainly want to know that your business can grow. That’s why founders spend so much time discussing TAM, Serviceable Addressable Market (SAM), and Serviceable Obtainable Market (SOM).
Those concepts matter.
Just not in the order many founders think.
Your Total Addressable Market tells investors that the opportunity is large enough to build a meaningful business.
Your Serviceable Addressable Market begins narrowing down the opportunity to customers you can realistically reach.
Your Serviceable Obtainable Market is where the conversation becomes real because it forces you to answer a far more difficult question.
Who is actually going to buy from you first?
Evidence Beats Market Size
Experienced investors know that ambitious projections are easy to build. What they really want is evidence that you’ve found a customer who urgently wants a problem solved and is willing to pay for that solution today.
Evidence is far more persuasive than optimism.
A founder who claims access to a trillion-dollar market but can’t explain why ten customers bought the product is asking investors to believe in possibilities.
A founder who can clearly explain why twenty remarkably similar customers purchased, renewed, and recommended the product is demonstrating something much more valuable.
They’ve reduced uncertainty.
Product-Market Fit Starts With Customer Clarity
That’s one of the reasons product-market fit is so often misunderstood.
People describe it as though a switch suddenly flips.
One day, nobody cares. The next day, customers seem to appear everywhere.
Founders who have lived through this usually describe something very different.
They’ll tell you that sales conversations became shorter because prospects immediately understood the problem being solved.
Customer interviews became more predictable because people described nearly identical frustrations.
Marketing became easier because the language customers naturally used was now reflected throughout the website, product demonstrations, and sales process.
Product demonstrations became less confrontational because priorities were no longer driven by opinions inside the company. They were driven by patterns observed across dozens of similar customers.
None of that happened because the founders became better marketers overnight.
It happened because they finally understood the customer deeply enough that every other part of the business became clearer.
People naturally focus on the product, but the real breakthrough usually happens much earlier in the lifecycle of the startup.
It happens when founders stop trying to understand everyone within a large, broad market and begin focusing on a small niche market of similar people with similar problems.
A Narrow First Market Makes the Whole Company Sharper
Everything downstream begins to improve.
Positioning becomes sharper because you’re speaking to one audience instead of several.
Marketing becomes more efficient because you know exactly where those customers spend their time and how they describe their problems.
Product development becomes more disciplined because every feature strengthens the same value proposition instead of satisfying unrelated customer requests.
Retention improves because customers feel as though the product was designed specifically for the way they work.
Referrals increase because people facing the same problem naturally know other people facing the same problem.
The business begins reinforcing itself.
Your First One Hundred Customers Should Sound Similar
That’s why I encourage founders to ask a different question before they write another line of code or ask AI to generate another feature.
Don’t ask whether your market is big enough.
Ask whether your first one hundred customers are likely to describe the same painful problem in almost the same words.
Can you identify exactly where those customers spend their time?
Do they already have workarounds because the problem is important enough that they’ve been forced to solve it themselves?
Will success with this group naturally open the door to an adjacent market that shares many of the same characteristics?
Most importantly, if you disappeared tomorrow, would those customers actively look for another solution because the problem is costing them time, money, or opportunity every single week?
If the answer to those questions is yes, you’ve found something far more valuable than a large market; you’ve found a market that can teach you.
And that’s what your first market is really for.
Not maximizing revenue, impressing investors, or proving how ambitious your vision is.
Its job is to accelerate your learning.
The faster you learn, the faster you can improve your product, and the faster your product improves, the sooner your customers begin recommending it to others, and the sooner that happens, the sooner expansion becomes a choice instead of a necessity.
Earn the Right to Expand
Eventually, you’ll move beyond your first market. You should. Every enduring company does.
But don’t expand because you’re impatient, expand because you’ve earned the right to.
When one community consistently chooses your product over every other available alternative, you’ve created something much more valuable than early revenue.
You’ve created evidence that you understand the needs of your customers.
That’s the foundation from which lasting companies are built.
The Best Founders Start With the Customer They Can Understand Best
The founders I admire most don’t begin by asking how many people could buy their product; they begin by asking which group of customers they can understand better than anyone else.
That difference sounds subtle. It isn’t.
One approach optimizes for reach. The other optimizes for learning.
In the earliest days of a startup, learning wins every time.
So, the next time someone asks you how large your market is, don’t begin with the biggest possible number.
Instead, tell them about the one group of customers who lose money, waste time, or go home frustrated because the problem you’re going to address still exists.
Tell them why those customers are different and why your product fits their needs better than any other existing alternative.
If you can do that convincingly, you’ve already answered the question that matters most.
Not how large your market could become, but where your startup should begin.
Because the most successful startups don’t grow by trying to matter to the masses.
They grow by becoming indispensable to a small group of people with a critical, unresolved need.
Everything else follows from there.
Become a paid subscriber to Winning Product / Winning Startup and get a FREE copy of The Product-Market Fit Assessment
Click the button above to view paid subscription options and the benefits that come with each.