A Commitment-to-Buy test asks prospects to sign a short, non-binding letter of intent saying they plan to buy your product or partner with you. It sits between a conversation and a contract. It’s easy to agree to, but formal enough that people have to think about whether they really mean it. That makes it one of the fastest ways to tell real demand from polite interest before you build.
Most teams spend months in discovery conversations with potential customers and partners. They collect enthusiasm, positive feedback and promises to “definitely consider it when you’re ready”. Then they build on that warm interest.
That approach mistakes politeness for commitment. Asking people to put their intentions in writing shows you who’s genuinely interested and who’s just being professionally courteous.
What is a Commitment-to-Buy test?
It’s a short written document, usually a one-page letter of intent, that asks a prospect to formally state their intention to buy or partner. It’s stronger than verbal interest but lighter than a contract, which makes it ideal for testing demand before you build.
Think of it as a business engagement ring: a formal sign of serious intent that either side can still walk away from, but which says far more than casual interest ever could.
How a logistics company avoided building for phantom demand
A logistics company we work with was developing a platform to automate supply chain monitoring for manufacturers. After six months of interviews with 45 prospects, the feedback looked overwhelming: 89% said they “definitely needed” the product and would “absolutely buy it” when it was ready.
Based on that feedback, they were preparing to invest £3M and spend 18 months building it. The interest felt rock-solid. Several prospects even shared detailed feature requirements and said they had the budget.
Before they started, we suggested they test real commitment. They wrote a simple one-page letter of intent asking prospects to formally state their intention to buy, with delivery expected in 12 months.
Of the 45 prospects who had shown strong interest, only 7 signed. That’s 16%, a gap that would have destroyed their business case.
Follow-up conversations explained why. Most prospects liked the idea but had concerns they hadn’t raised in discovery calls: budget approval processes, integration complexity, competing priorities and nervousness about using a new supplier. All of it surfaced the moment they were asked to commit in writing.
What they did instead
Instead of building a full platform, they repositioned around pilots. Their new letter of intent asked prospects to commit to a 90-day proof of concept. This time, 23 prospects signed up for pilot programmes, a much stronger foundation to build and scale from.
Is your business case built on positive conversations?
If your evidence for a new product rests on interviews and verbal interest, it’s worth a conversation about how to test real commitment before you invest. Miles, Managing Partner at Future Foundry, can walk through whether a Commitment-to-Buy test, or another business experimentation method, fits your situation.
Book a call with Miles here.
Why written commitment reveals what conversations miss
The gap between verbal interest and written commitment isn’t about dishonesty. It’s about how decisions really get made. When someone commits formally, even without a binding contract, they have to think about things that never come up in hypothetical conversations. We’ve written more about the polite lies customers tell in surveys.
1. New people get involved
Early conversations usually happen with innovation teams who enjoy exploring new ideas. A written commitment pulls in procurement, legal and budget holders who weren’t part of those calls. They bring different concerns about supplier risk, implementation effort and where money and people should go.
2. Competing priorities come into view
A commitment forces prospects to weigh your product against everything else competing for the same budget and attention. Plenty of ideas that feel urgent in conversation become less pressing when they sit next to several other “urgent” projects.
3. Timelines become real
It’s easy to be enthusiastic about something that might arrive “someday”. A letter of intent with a delivery date makes prospects think through when they’d actually implement it, what would need to change and how much disruption it would cause.
How to write a letter of intent that tests real demand
The aim is a commitment that needs real thought, without barriers so high nobody signs.
1. Keep it to one page and clearly non-binding
It should be clearly non-binding, but formal enough that people consider what they actually intend rather than just being polite.
2. Add specific but reasonable conditions
Avoid open-ended commitments. Set out a timeframe, basic terms and your key assumptions. Something like “intent to evaluate [product] for purchase when available in [timeframe], subject to [key conditions]” gives structure without asking for detailed specifications.
3. Send it to people with budget authority
Ask the people who control the budget and will implement it, not just the people who enjoy exploring new ideas. You’re testing purchase intent, not curiosity.
What to include:
What you’re offering: a plain description of the product or service
When: the expected delivery date or timeframe
The basic terms: the main conditions or assumptions the commitment depends on
A clear non-binding statement: so nobody worries they’re signing a contract
Who’s signing: the name and role of someone with budget authority
What commitment rates tell you about your market
Don’t expect high conversion from verbal interest to written commitment. In most B2B markets, even 20–30% can signal strong demand. The logistics team’s 16%, against a business case built on 89%, was the real warning sign. The goal isn’t to maximise signatures. It’s to understand the gap between what people say and what they’ll actually commit to.
A low commitment rate often points to timing rather than a bad product. Prospects may love the idea but lack the budget, process, capacity or internal agreement needed to adopt it. Knowing that helps you adjust your timing, positioning or route to market.
A small number of real commitments is worth more than a large number of polite ones. Seven signatures teach you more about real demand than 45 enthusiastic conversations. We’ve seen the same pattern with email metrics, where engagement looked strong but very few people went on to try the product.
When commitment testing works best
It works especially well for B2B products with complex buying processes, where several people influence the decision and adoption needs real organisational change. It’s also useful for testing partnerships before you commit development resources, whether with suppliers, distributors or strategic partners.
Timing matters too. Use it after positive discovery conversations or after a co-design workshop shows you what buyers prioritise, but before any major development investment. You want prospects who understand your idea and have shown interest, but haven’t yet made formal buying decisions.
For consumer products, the equivalent is asking people to pay upfront, through an Advance Purchase or a crowdfunding campaign.
Where should you start?
Pick 10 to 15 prospects who have shown strong verbal interest in your current project. Write a simple, one-page, non-binding letter of intent with reasonable terms and a timeline.
Focus less on how many people sign and more on why people sign or decline. Both answers tell you a lot about how your buyers decide, what competes for their attention, and whether they’re ready to implement.
Most teams stop at verbal interest. The successful ones test written commitment before they build.
Common questions about letters of intent
Is a letter of intent legally binding?
It’s designed not to be, so say clearly in the document that it’s non-binding. Wording matters, though, so ask your legal team to check your template before you send it.
What’s a good conversion rate from interest to a signed letter of intent?
In most B2B markets, 20–30% of interested prospects signing can signal strong demand. What matters more is the gap between how many people said yes in conversation and how many committed in writing.
What’s the difference between a letter of intent and a pre-order?
A letter of intent is a written statement of intent with no money involved. A pre-order, or Advance Purchase, asks customers to pay upfront, which is an even stronger signal. Letters of intent tend to suit B2B buyers, while pre-orders suit consumer products.
Is your business case built on positive conversations?
If your evidence for a new product rests on interviews and verbal interest, it’s worth a conversation about how to test real commitment before you invest. Miles, Managing Partner at Future Foundry, can walk through whether a Commitment-to-Buy test, or another business experimentation method, fits your situation.
Book a call with Miles here.
A Commitment-to-Buy test is one method within business experimentation, the discipline of testing what customers actually do before committing budget to a solution. Explore the Commitment-to-Buy test and 50+ other methods in our Experiment Toolbox.
