Every founder thinks they’ve found a gap in the market. Most of them are wrong — not because the gap doesn’t exist, but because not every gap is worth filling.
I once identified a “gap” for project management software designed specifically for magicians. I’m a magician. I know the workflow. Nobody was serving this market. Classic gap, right? Except the total addressable market was tiny, magicians hate paying for software, and the existing tools (a spreadsheet and a notebook) worked well enough that the pain wasn’t worth solving for.
Gap identified. Business case absent. Lesson learned.
After 20+ years of evaluating business opportunities — both my own and dozens of others through consulting and the Startup Burgenland accelerator — I’ve developed a filter that separates real opportunities from phantom ones. Here’s how it works.
The Gap Is Not the Opportunity
A market gap is a space where no product currently exists. An opportunity is a gap where people are actively trying to solve the problem and willing to pay someone who solves it better.
These are very different things. The gap between “no product exists” and “people will pay for a product” is where most business ideas go to die.
Here’s a mental model that helps: imagine a four-quadrant grid.
Top-left: Gap exists, demand exists. This is where real opportunities live. Nobody is serving this need well, and people are actively looking for solutions. These are rare and you should move fast when you find one.
Top-right: No gap, demand exists. The market is served but customers are unsatisfied. This is an improvement opportunity, not a creation opportunity. You need to be significantly better than existing options to win here.
Bottom-left: Gap exists, no demand. This is the trap. The gap looks exciting because nobody is here. But nobody is here because nobody cares. This is the magician project management software quadrant.
Bottom-right: No gap, no demand. Nothing to see here.
Most founders get excited about bottom-left opportunities because the gap is clearly visible. The absence of competitors feels like a signal. But absence of competitors often means absence of customers. Before celebrating an empty market, ask yourself: “Is this empty because nobody’s thought of it, or because everybody who has thought of it realized it won’t work?”
The honest answer is usually the second one. This is why validation through customer behavior matters more than market analysis. Markets don’t tell you anything. Customers do.
The Five Filters for Real Opportunities
I run every potential opportunity through five filters. If it passes all five, it’s worth testing. If it fails any one of them, it needs more investigation before committing time.
Filter 1: People are already spending money on bad solutions.
This is the strongest possible signal. If someone is paying for something that doesn’t fully solve their problem, you know three things: the problem is real, the problem is urgent enough to justify spending, and customers are reachable (they’re already buying from someone).
How do I check this? I look for products with mediocre reviews. I search for Reddit threads where people complain about existing tools. I ask potential customers “How do you currently handle this? What do you spend on it?” Direct conversation mining is the fastest way to find this signal.
Filter 2: The problem is recurring, not one-time.
A problem someone faces once creates a one-time purchase. A problem someone faces weekly or monthly creates subscription revenue. The best businesses solve recurring problems because acquisition costs are amortized over a long customer lifetime.
Ask: “How often do you deal with this?” If the answer is “once a year,” the math probably doesn’t work for a standalone product. If the answer is “every week,” you’ve got something.
Filter 3: You can reach the target customer affordably.
A brilliant product for a customer you can’t reach is worthless. Before assessing the product opportunity, assess the distribution opportunity. Where do these people spend time? Can you get in front of them without spending a fortune?
The best opportunities are in markets where customers self-identify and congregate. They’re in specific subreddits, specific LinkedIn groups, specific conferences. If your target customer is “anyone who wants to be more productive,” good luck finding them. If your target customer is “freelance graphic designers in German-speaking countries who use Figma,” you can find them in an afternoon.
Filter 4: The problem has emotional weight.
Humans make purchasing decisions emotionally and justify them rationally. If the problem you’re solving generates frustration, fear, embarrassment, or aspiration, people will pay to solve it. If the problem generates mild annoyance, they’ll shrug and work around it.
How do I gauge emotional weight? I listen to the language people use. “It’s kind of annoying” is low emotional weight. “I dread doing this every Monday” is high emotional weight. “I lost a client because of this” is very high. The language reveals the intensity, and intensity predicts willingness to pay.
Filter 5: You have an unfair advantage in this space.
This doesn’t mean you need to be an expert. It means you need some reason why you can serve this market better than a random person could. Maybe you are the target customer (scratching your own itch). Maybe you have a relevant network. Maybe you have domain expertise from your career. Maybe you’ve built something similar before.
If you have no advantage, you’ll compete purely on execution speed and marketing budget — and someone with more resources will eventually overtake you. The subtraction audit approach helps here too: strip away opportunities where you have no edge.
Where to Look for Gaps
Knowing the filters is one thing. Knowing where to point them is another. Here are the six places I consistently find real opportunities.
Place 1: Industry transitions.
When an industry shifts — new regulation, new technology, demographic change — gaps open up temporarily. The companies serving the old paradigm haven’t adapted yet, and the customers in the new paradigm are underserved.
Example: When Austria tightened data privacy regulations, every small business suddenly needed compliance help. The existing compliance consultants were expensive and enterprise-focused. The gap for affordable, SME-focused compliance guidance was wide open.
Place 2: Successful products with angry user bases.
Go to G2, Trustpilot, or App Store reviews for popular products in your space. Sort by one-star reviews. Read the complaints. If hundreds of people are complaining about the same thing, that’s a feature gap in an established market with proven demand.
Place 3: Excel spreadsheet graveyards.
Whenever you see someone managing a business process in a spreadsheet, you’re looking at an opportunity. Spreadsheets are where people go when no purpose-built tool exists. The spreadsheet is their admission that the problem matters enough to solve but nobody has solved it well enough yet.
Place 4: Professional communities.
Join Slack groups, Discord servers, and forums for your target profession. Lurk. Read what people ask for help with repeatedly. The questions that come up every week are problems that no product has solved. They’re not complaining about it because they’ve accepted it as part of the job. That acceptance is your opportunity.
Place 5: Adjacent to successful products.
Every successful product has customers who need something slightly different. Canva is great for non-designers but frustrating for anyone who needs precise brand control. Shopify serves most e-commerce needs but underserves subscription businesses. Look at what’s adjacent to popular tools and see who’s falling through the cracks.
Place 6: Your own frustrations at work.
The most validated opportunities I’ve ever seen started with a founder saying “I built this for myself.” When you experience the problem firsthand, you have intimate knowledge of the pain, instant access to a peer group who shares it, and the motivation to stick with a hard problem. Starting from your own experience gives you a natural unfair advantage.
Sizing the Opportunity Without Fancy Research
You don’t need a TAM/SAM/SOM analysis or a €50,000 market research report. You need a napkin calculation.
Here’s mine:
Number of potential customers: How many people have this problem? Use proxies — LinkedIn job title counts, subreddit membership numbers, industry association membership statistics.
Conversion estimate: Assume 1-3% of people who see your offer will buy. This is conservative for a well-targeted audience.
Price point: What would you charge? (Use the anchor from Filter 1 — what are people already spending on bad solutions?)
Revenue estimate: Potential customers × Conversion rate × Price = Annual revenue potential
Let’s say there are 50,000 freelance graphic designers in German-speaking Europe. 2% conversion at €29/month = 1,000 customers × €348/year = €348,000 annual revenue. Is that enough for you? If you’re a solo founder, absolutely. If you’re trying to build a venture-scale company, probably not.
This napkin math won’t be accurate. It doesn’t need to be. It needs to tell you whether the opportunity is in the right ballpark. If the napkin says €10,000/year even with optimistic assumptions, move on. If it says €500,000/year with conservative assumptions, start validating.
The “Anti-Gap” — When to Walk Away
Not every gap should be filled. Here are the gaps I actively avoid.
Gaps that require educating the market. If you need to convince people they have a problem before you can sell them the solution, you’ll spend all your marketing budget on education rather than conversion. Let someone else educate. You come in after the market is aware.
Gaps in dying markets. A gap in the fax machine industry is still a gap in a dying market. Make sure the trend line is going up, not down.
Gaps that only exist because of bad timing. Some problems are seasonal or cyclical. If the gap exists because you’re looking at it during peak pain but disappears during other months, your revenue will be wildly inconsistent.
Gaps where the customer is not the buyer. In healthcare, the patient has the problem but the insurance company makes the purchasing decision. In education, the student has the problem but the school buys the solution. These gaps have an extra layer of complexity that makes validation much harder. Not impossible — just harder. Factor that into your decision.
Key Takeaways
- A market gap is not a business opportunity. An opportunity exists only when people are actively trying to solve the problem and willing to pay for a better solution.
- Run every opportunity through five filters: existing spend on bad solutions, recurring problem, reachable customers, emotional weight, and your unfair advantage.
- Look in six specific places: industry transitions, angry user reviews, spreadsheet graveyards, professional communities, adjacent to successful products, and your own work frustrations.
- Use napkin math, not market research reports. Potential customers × 2% conversion × price per year tells you if the opportunity is worth pursuing.
- Walk away from gaps that require market education, exist in dying markets, or have misaligned buyer/user dynamics. Not every gap deserves your time.
