Finding product-market fit: When the journey isn’t straightforward

Many founders think product-market fit (PMF) will feel like a breakthrough: a sudden alignment between what you’ve built and what the market wants. In startup lore, it arrives cleanly and decisively, often just in time to unlock growth, fundraising, or both.

In reality, product-market fit rarely announces itself so clearly. More often, it emerges slowly, through a series of false starts, partial signals, and uncomfortable questions. Founders may feel like their startup is close to product-market fit long before they actually reach it. Or they may dismiss real traction because it doesn’t match the story they expected to tell.

This article explores a more honest version of the product-market fit journey, one that reflects how early-stage founders actually experience it: as nonlinear, ambiguous, and deeply iterative. Drawing on established frameworks and examples for navigating early-stage uncertainty, the goal here isn’t to define product-market fit perfectly, but to help you recognize where your business truly stands, what product-market fit feels like, and what to do next.

Product-market fit is often reduced to a single quote or metric. Early definitions of the term, embraced by Y Combinator, often describe it as a moment when customers “pull” the product. You may also hear product-market fit described as the point when growth becomes inevitable. 

These descriptions are useful, but incomplete. In practice, product-market fit exists on a spectrum. Early-stage companies often experience partial product-market fit before they achieve anything durable. For instance, a narrow group of customers may find real value, while others remain indifferent. Usage may spike during onboarding, then flatten. Retention may look promising in one segment and shaky in another. This ambiguity is why many founders struggle with how to find product-market fit in the early stages. 

Think of product-market fit as a process and a pattern that emerges over time, not as a single moment of arrival. Your approach will sharpen as your understanding of your customers, the problem you’re solving, and the solution all come together through an iterative startup journey. The signals are rarely definitive and, instead, require interpretation, context, and patience, all while challenging early assumptions about what your startup’s product-market fit will look like.

One of the hardest parts of the startup product-market fit journey is learning which signals matter and which don’t. These early indicators might feel encouraging, but fail to translate into real traction.

Interest without urgency

Prospective customers may say the product is interesting, clever, or impressive, but hesitate to change their behavior or pay for it. This type of interest can be a misleading signal, since the interest isn’t paired with conversion.

Sign-ups without retention

A growing top-of-funnel can mask the reality that users aren’t sticking around or forming habits. This is a reminder that sign-ups alone aren’t meaningful customer retention indicators.

Positive feedback without repeat usage

Praise feels validating, but it doesn’t always correlate with value delivered. Founders at trust-management platform Vanta reflected on this dynamic in a First Round Review article about their path to product-market fit. Early inbound interest suggested that they were solving a real problem. But it wasn’t until they observed consistent buying behavior and repeat engagement that they understood which customers truly felt the pain the company was addressing. Upon realizing this, the Vanta team took a new approach.

“We decided we weren’t allowed to build anything at all,” Christina Cacioppo, founder and CEO of Vanta, told First Round Review. “We had to just talk to people — and talk to them until we had a lot of confidence and a mental model of customers, their jobs, the problems they might have, and how we might solve them.”

The lesson here isn’t that early signals are meaningless, but that it’s important to test them against stronger indicators, such as:

• Word-of-mouth referrals
• Repeat usage over time
• Willingness to switch from an existing solution
• Customers pulling you deeper into their workflow through clear product feedback loops

These tend to develop more slowly, but they are examples of more reliable PMF signs and signals.

If misleading signals are common, what should founders watch for instead? To get closer to finding your product-market fit, shift from an emphasis on volume to focus. Progress toward PMF often shows up as increasing clarity, not just increasing numbers. 

To begin to get more clear on areas that feel fuzzy, ask questions like:

• Who gets the most value from this product?
• What problem are they actually buying it to solve?
• Why do they choose it over alternatives?
• What would cause them to churn?

When measuring product-market fit, the emphasis shouldn’t be on a single metric. Instead, look for patterns, especially startup traction metrics that repeat across cohorts. For instance, this might be retention cohorts that stabilize or customer feedback that converges around a specific use case. Later, you might notice growth that becomes easier to explain — and easier to repeat.

For startup validation, narrow wins in the right segment often matter more than gaining broad appeal too early, particularly when you’re trying to confirm whether you’re truly building the right thing.

Many founders think they’ve figured out how to find product-market fit, only to discover later that their landing wasn’t as solid as it seemed. Navigating failed PMF assumptions is a normal part of the iterative startup journey.

For example, the founders of Linear, a project management and issue-tracking software, described a period where usage was growing and customers were engaged, yet something still felt off. The product was useful, but not essential. Eventually, they saw progress after, they narrowed their scope and committed to a more specific audience and set of problems. “If you don’t want to grow to more customer types, you can sell more to existing customers,” Karri Saarinen, CEO and co-founder of Linear, told First Round Review. “That’s what we’ve done.”

This kind of course correction is common. Founders often need to let go of appealing ideas, secondary use cases, or broader markets in order to strengthen their core value proposition. Even though it can feel like slowing down, this approach is often the fastest way to get real traction and a necessary step to take before successfully pivoting to product-market fit.

When signals are mixed, founders face a difficult decision: Is it time to push forward or to pause and re-evaluate? The most effective course corrections tend to be small, deliberate, and grounded in learning. And most early-stage founder advice prioritizes clarity over speed.

Run focused experiments

Test one assumption at a time. Change onboarding, pricing, or positioning in isolation, so the results are interpretable.

Revisit the core pain point

What is the main pain point that your product is seeking to solve? Validate whether customers feel the problem acutely enough to prioritize solving it now.

Be willing to outgrow earlier ideas

Features, segments, or narratives that once felt exciting may be distracting you from what actually works. It’s a common pattern in founder pivots that don’t look dramatic from the outside.

Pivots don’t have to be dramatic to be meaningful. Often, the most impactful shifts are subtle changes, such as refining how you define success, getting clearer on who you’re building for, or taking a quieter go-to-market approach. Knowing how and why to pivot makes it easier to adjust, without abandoning the progress you’ve already made.

The stretch between early validation and true product-market fit is often the most psychologically demanding part of building a company.

Founders may feel pressure to declare product-market fit too early, especially when fundraising timelines loom. But rushing the narrative can lock teams into assumptions that aren’t fully tested, making it harder to spot genuine signs of product-market fit later.

To avoid making a decision that’s hard to undo later:

• Don’t confuse momentum with inevitability.
• Create structures that reveal real customer behavior.
• Validate pain, not just praise.

These frameworks help founders stay grounded when clarity is scarce. They also reinforce an important truth: Wandering is not failing. Exploration is part of building the right thing.

Despite the ambiguity that often comes with this process, there are encouraging signals that often appear as product-market fit approaches. Look for these signs:

• Customers describe your product in their own words, consistently.
• Use cases converge, rather than expand endlessly.
• Retention improves within a specific cohort, supported by strong customer retention indicators.
• Sales cycles shorten as objections fade.

These PMF signs and signals don’t guarantee success, but they suggest that alignment is forming. For founders navigating startup product-market fit, recognizing these signals can restore confidence and focus at a critical moment.

Product-market fit rarely arrives as a single breakthrough moment. Early signals — like interest, sign-ups, or positive feedback — can feel promising, but they don’t always reflect real demand or double as reliable startup traction metrics.

More dependable indicators tend to emerge gradually, such as consistent retention within a specific customer group, clearer and more repeatable use cases, shorter sales cycles, and customers integrating the product more deeply into their workflows. 

When those signals aren’t there yet, the work often isn’t about pushing harder, but about sharpening focus, validating the core pain point again, and running deliberate experiments to test what truly matters to your target audience. Product-market fit tends to emerge over time, and you can spot it by recognizing patterns, making strategic course corrections, and measuring the right metrics.

Product-market fit isn’t a destination you arrive at once and for all. Markets evolve, customers change, and products must adapt in an ongoing cycle. Reaching a durable version of product-market fit gives founders leverage: clarity in decision-making, confidence in investment, and momentum that compounds. However, if you’re early in the journey, uncertainty is normal, not a red flag. 

Mercury supports founders through these uncertain stages, not just once things are obvious or easy. Whether you’re validating assumptions, refining your business model, or preparing for a go-to-market pivot, the goal is the same: to build something that truly earns its place in your customers’ lives.