Before spending €15,000 on a V1, validate your idea for under €500 in one to two weeks. The rule is simple: a signal only counts if it costs your prospect something — money, time, or a committing piece of data. A free “great idea!” is worthless; a paid pre-order, an email left to be notified at launch, or a booked call are worth gold. Here are the four methods that work, and the traps to avoid.
Problem interviews (5 to 10 are enough)
Talk to 5 to 10 people in your target audience before writing a single line of code. The goal is not to pitch your solution but to understand the problem: how do they solve it today, what does it cost them, what have they already tried. Ask about the past, never about the future.
- Good signal: the person describes a painful, recent problem and already pays for a clumsy workaround.
- Bad signal: a polite “yeah, that would be nice.” The conditional tense is a red light.
- Do this: ask “tell me about the last time you…” rather than “would you use…”
Landing page + pre-registrations
Build a landing page in a day (Webflow, Framer, or Next.js on Vercel) that states the promise, the benefit, and a single call to action: leave an email. Send targeted traffic to it — a few hundred euros of ads or three posts in the right communities. The visitor-to-email conversion rate tells you whether the message resonates.
A benchmark: on cold, qualified traffic, a signup rate of 15 to 30% is a real signal. Below 5%, your promise or your audience need rethinking before you invest.
Pre-sales: the one signal that never lies
Nothing validates an idea like a payment. Offer a discounted pre-sale (“founding member”), a refundable deposit, or a signed letter of intent in B2B. Someone who pulls out their card before the product even exists confirms two things: the problem is real and your price holds.
The only vote that counts is the one people pay for. Everything else is just a polite compliment.
The fake door test
Add a “Buy” or “Enable feature” button on your landing that leads not to the product but to a “Coming soon — leave your email” message. You measure real intent, not stated intent. It is ethical as long as no one is charged and the wait is short.
Which signals deceive
- Praise from friends and family: emotional bias, zero value.
- Likes and views: attention, not purchase intent.
- “I’d try it” with no follow-through: stated intent always overstates the real thing.
- A massive survey with no commitment: a thousand free answers weigh less than ten deposits.
Once you have a paying signal, you are no longer investing blindly. That is the moment to move to a real production V1 — at Khufu, a fixed-price package of €15,000, delivered in 7 days — to turn validated demand into a product your first customers can use right away.