Will my app make money, and when should I stop?

The six things, with how Prep66 scored

1. A problem they must solve. The regulator requires the exam. Nobody had to be convinced that they needed to prepare.
2. A deadline. An exam date turns "someday" into "this month". It is why Prep66's first payers bought within minutes of landing on the page instead of thinking about it for weeks.
3. A painful cost of failure. Failing a module means a resit fee, months lost, a stalled licence and a delayed pay rise. Next to that, £19.99 a month is not a purchase. It is insurance. Buyers compare the price with the cost of failing, not with other products.
4. Expensive or bad alternatives. The competition was courses at £300 and more, and scanned PDF dumps. Prep66 was the cheap option, and far deeper than the free material.
5. Trust. Built by someone who had sat those exams, with over 25,000 questions across every module. A candidate could tell that within thirty seconds, which is why the landing page alone was enough to win the first customer.
6. Buyers you can reach. The candidates gather in a few subreddits, asking how to study for each module. The founder knew exactly where, because he had been one of them.

What each one does for you

You do not need all six. The two you cannot do without are a problem the buyer already knows they have, and enough trust to hand over a card. The other four each make selling easier when they are there. A deadline makes people buy now instead of later. A painful failure makes them accept a higher price. Weak alternatives leave you room on price. Buyers you can reach mean customers you do not have to pay for.

A business with money can make up for the missing ones with brand spending and ads. A solo builder with no ad budget cannot. So for you, a deadline and buyers you can reach are close to essential as well. Your real filter is four things: a known problem, a deadline, trust you have or can honestly borrow, and buyers gathered somewhere you can reach for free.

If your product is nothing like Prep66

Prep66 is a cheap product that one person buys alone on the page, so the six apply to it literally. Another kind of product asks the same six questions in its own form. A problem the buyer must solve can be a rule their company has to follow. A deadline can be a renewal, an audit, a budget year, a season, or a moment in someone's life. Trust can be star ratings and recent reviews for a phone product, or a security review and a reference customer when a company buys. A no on one of the six only matters where that thing decides the sale for your kind of product.

Painkiller or vitamin

If nobody needs your product today, no marketing will fix that. Ancestorii was a vitamin. People on Reddit called it meaningful, important and beautiful, and nobody said they needed it right now. "This is nice, I'll come back to it later" means later never comes. It has 177 signups and has never had a paying customer.

Ask not only whether the problem hurts, but when it bites. A nice to have can still sell at the moment it bites: a birthday, a death, a move, an audit. A game, or anything people use out of habit, is different again: it lives on whether people come back, not on pain.

A pressing problem makes up for missing trust

Prep66's first customer paid on a website that was nine days old, without trying a single question, because the exam was closer than the doubt. For a cheap product, trust can be built in a weekend: a clean design, a company voice, a proper domain, a checkout people recognise. Where the buyer is handing over health records, money, private data or a big contract, trust takes paperwork, proof and time. Ancestorii asked families for their memories and never earned that trust. A pressing problem cannot be invented, but trust can be built. So look for the problem first. Trust is the easier fix.

When to stop

• Stop building when no stranger has used it. If not one stranger has done the core thing for free, a new feature is not the answer. Ancestorii printed memory books while no stranger had uploaded a single memory.
• Act on the first real answer. Decide the size of each test and the result that stops it before it starts, then act when that result comes. Ancestorii's founder could see in the first week that it was dead, and kept going on hope.
• Say it has no market, out loud. When the same fair test has been run several times and nothing has come back, the product has no market, and it is time to move on. Each of those tests has to have been big enough to show a sale if one was there, and run on a channel that suits the buyer and the price. If the tests were too small to tell, say that instead.

And first, the honest question: do you want this to make money, or is it a project you love working on? Both are fine. The answer changes everything you do next.