Validation guides
How to Validate a Product Idea: Interviews and a Paid Pilot
Domain experts have an advantage most founders do not: they already know the buyers. The risk is assuming what those buyers will pay for. Two steps fix that: structured interviews, then a paid pilot.
To validate a product idea, interview people in the target role about the last time they had the problem and what it cost, then offer the most interested a paid pilot with a success metric, dates and post-pilot pricing agreed in advance. A signed, paid pilot is the strongest evidence you can get before building the full product.
This guide is written for professionals turning expertise into a product: clinicians, lawyers, engineers, accountants, operators. You know the problem. The question is whether your version of the solution is one people will pay for.
Key takeaways
- Your expertise is a head start, not evidence. Buyers' behaviour is the evidence.
- Interview about the past, not your idea: the last occurrence, the workaround, the cost.
- Ask for a commitment at the end of every call.
- A paid pilot needs four things agreed first: metric, dates, price after, and who decides.
- Deliver the pilot by hand if you must. You are testing the outcome, not the software.
Why do domain experts need to validate product ideas at all?
Because knowing a problem well is different from knowing what buyers will pay to fix. Experts often overestimate how much others feel a pain they feel themselves.
Paul Graham's advice is to look for "problems, preferably problems you have yourself" (Paul Graham), and domain experts are well placed to do that. The trap is the next step: assuming colleagues share your priorities, your budget authority and your willingness to change how they work.
Validation separates the two. Your expertise tells you what to ask. The buyers' answers tell you whether to build.
How do you run validation interviews as an expert?
Talk to people in the role you plan to sell to, ask about specific recent experiences, and resist the urge to diagnose or pitch. Your job in the interview is to listen.
Experts are used to being the one with answers, which makes this harder than it sounds. Follow The Mom Test rules, as summarised by Sachin Rekhi: talk about their life instead of your idea, ask about specifics in the past instead of opinions about the future, and ask for commitments.
Questions that work:
- When did this last happen? Walk me through it.
- What did you do, and what did it cost in time or money?
- What have you tried before? Why did it not stick?
- Who else is affected, and who would approve spending to fix it?
- Would you be open to trying a small paid version with us?
Write up every call the same day. Our list of customer interview questions has more.
How do you set up a paid pilot?
Scope it small, time-box it, agree one success metric against today's baseline, and agree the paid terms that follow if the metric is met, before anything starts.
| Term | What to agree |
|---|---|
| Scope | One team, one workflow, one problem |
| Success metric | One number, measured against today's baseline |
| Dates | Start, midpoint check-in, end |
| Pilot fee | Paid, even if small; it tests budget authority |
| What they provide | Data, access and a named contact |
| After the pilot | The paid terms that start if the metric is met |
| Decision maker | The name of the person who signs |
Charge for the pilot. A free pilot tests whether people will accept something free. A paid one tests whether someone with a budget believes the outcome is worth money.
Do you need a product to run a pilot?
No. Many pilots are delivered partly or wholly by hand. You are testing whether the outcome is valuable, and you learn more by doing the work yourself.
Paul Graham's essay on unscalable work makes the case: "The most common unscalable thing founders have to do at the start is to recruit users manually" (Paul Graham). The same applies to delivery. Doing the work by hand, with spreadsheets, your own expertise and simple tools, shows you exactly which steps are worth automating.
Be honest with the customer about how the pilot is delivered. What they are paying for is the outcome.
How do you read the results of interviews and a pilot?
Interviews tell you whether the problem is shared and costly. The pilot tells you whether your solution moves a metric the buyer cares about and whether they will pay to keep it.
| Result | What it means | Next step |
|---|---|---|
| Pilot met its metric and converted to paid | Validated for this buyer | Build the product around what you did by hand |
| Pilot met its metric, buyer will not pay | Value exists; budget, price or decision maker is wrong | Revisit who signs and the price |
| Pilot missed its metric | The solution does not yet solve the problem | Change the approach before building |
| Nobody would agree to a paid pilot | The pain is not urgent enough, or you have the wrong buyer | Go back to interviews |
Where does NELL help a domain expert validate an idea?
Before and between these steps. NELL does the market research, competitor pricing and scoring, so your interviews and pilot focus on the assumptions most likely to fail.
Start with a free Quick Validate for a first read. DeepValidate adds sourced research on competitors, market size and demand, and names the risks to test first. See a full example in the sample report.
Frequently asked questions
How many interviews should I do before offering a pilot?
Enough that the same problem, described the same way by people in the same role, keeps coming up. Offer a pilot to the people who described it most urgently and have budget authority.
Should a pilot be free or paid?
Paid, even if the fee is small. A paid pilot tests budget authority and seriousness; a free one mostly tests whether people accept free things.
How long should a paid pilot last?
Long enough to measure the success metric against the baseline, and no longer. Agree the end date before starting so the pilot does not drift.
Can I validate a product idea with my own clients?
Yes, and they are often the best place to start. Be aware that existing relationships make people kinder, so rely on commitments like paid pilots more than on what they say.
What if my pilot customer wants custom features?
Note every request, but only build what several buyers would need. Custom work for one pilot can turn a product into a consulting project.
Start where you are
Your expertise tells you what to ask. A first read tells you where to start.
Sources
- Paul Graham, How to Get Startup Ideas (2012)
- Paul Graham, Do Things That Don't Scale (2013)
- Sachin Rekhi, A Primer on Talking to Customers From The Mom Test
This guide describes a general validation approach. Professional, regulatory and confidentiality rules in your field may limit how you run interviews or pilots; check them first.