Greenbox delivers weekly produce boxes from local farms to 200 subscribers in Perth. Recent customer interviews revealed that people stay for the convenience – not the local sourcing the team assumed. Now the team needs to find out what else they believe that they haven’t actually tested.
The JTBD interviews gave the Greenbox team a breakthrough. Subscribers don’t stay for fresh local vegetables. They stay because Greenbox eliminates weeknight dinner stress. The box arrives, dinner is decided, one less thing to worry about.
That insight reshaped the product roadmap. Recipe cards went into every box. Churn dropped from 8% to 5% in the first month.
But the interviews also revealed something less comfortable: a lot of what the team believes about the business is assumption, not fact.
Maya believes subscribers value local sourcing. She built the entire brand around it. Tom believes the substitution algorithm is good enough. Sam believes word-of-mouth is the main acquisition channel. Priya believes the weekly delivery cadence is right.
These aren’t minor details. They’re foundational assumptions. If any of them are wrong, the team could be optimising the wrong things for the next six months.
How assumptions hide
The tricky thing about assumptions is that the team doesn’t experience them as assumptions. They experience them as facts. “Subscribers value local sourcing” doesn’t feel like a guess – it feels like the foundation of the business. Maya would have said, with total confidence, that local sourcing is why people subscribe. Until the JTBD interviews showed otherwise.
The ones you’re most confident about are often the ones you’ve tested least. Nobody tests what they consider obvious.
Introducing Assumption Mapping
Assumption Mapping is a structured way to surface, categorise, and prioritise what you believe but haven’t validated.
Step 1: List your assumptions. Everything the team believes about the business. No judgement.
Step 2: Rate each on two axes. How critical is it? (If wrong, how badly does it hurt?) How much evidence? (Tested, or just a feeling?)
Step 3: Plot on a 2x2 grid.
Horizontal axis: Low Evidence → High Evidence. Vertical axis: Low Risk → High Risk.
The top-left quadrant – high risk, low evidence – is where the landmines live.
Running the session
Lee facilitates. Dave is here. Maya invited him after the JTBD interviews – partly because the assumptions about farms need a farmer’s perspective, and partly because Dave has a way of saying things that cut through the noise. He drove in from Margaret River this morning, two hours in his ute with ABC Country playing the whole way. He sits at the end of the table in his work shirt, arms folded, watching the team arrange their sticky notes. He hasn’t been in this office since the Event Storm months ago. The walls are different now – covered in printouts and JTBD transcripts. Patrick’s quote is pinned above the whiteboard: “I was paying twenty-five dollars a week to feel bad about myself.”
Dave reads it. He doesn’t say anything.
“Write down everything you believe about Greenbox that you haven’t actually tested,” Lee says. “Not features. Beliefs. Things you’d bet the business on.”
The team writes for ten minutes. Twenty-four assumptions pile up:
Maya: Subscribers value local sourcing. Farms will scale with us. Our price ($25/box) is competitive. Subscribers prefer curated over choosing. The brand matters more than the price.
Tom: The substitution algorithm produces acceptable results. The platform can handle 1,000 subscribers. Farms will use the portal. Weekly delivery is the right cadence.
Priya: Subscribers want more variety. Mobile is primary for account management. The signup conversion rate is acceptable.
Sam: Word-of-mouth is our primary channel. Subscribers would recommend us. Instagram drives sign-ups. Churn is value-driven, not logistics-driven.
Dave writes slowly. Three notes in large, deliberate handwriting: Farms will scale with us. We’re the only option. Farmers will keep supplying if Greenbox has a bad quarter.
Sam sees Dave’s second note and writes his own version: “We don’t have a serious competitor in Perth.”
Plotting the map
The team takes each assumption and debates where it belongs. This is where the interesting conversations happen.
“Subscribers value local sourcing.”
Maya instinctively puts it top-right: high risk, high evidence. “It’s our brand identity.”
Lee pushes back. “How many JTBD interviewees mentioned it as the primary reason they subscribe?”
Sam checks the LLM’s analysis. Local sourcing appeared in nine of fifteen interviews – but as the primary motivator in only three.
The assumption moves to the top-left. High risk, low evidence.
That move is uncomfortable. Maya built Greenbox around local sourcing. It’s not just a feature – it’s personal. Discovering that subscribers might not share that belief feels like a challenge to her identity, not just her business strategy.
“The substitution algorithm produces acceptable results.”
Tom puts it top-right. “Nobody complains.”
Priya raises her hand. “Nobody complains to us. But three churned subscribers in the JTBD interviews mentioned getting items they didn’t want. One said ‘I got turnips three weeks in a row.’”
Tom opens his laptop. Thirty seconds: “Turnips were available in bulk from Dave’s farm for three weeks. The algorithm scored them as the best substitution because they were cheap and plentiful. Root-for-root swaps. Technically correct. Terrible customer experience.”
The assumption moves left. Working correctly and working well are different things.
“Farms will scale with us as we grow.”
Maya puts it top-right. “I talk to Dave and Rachel every week. They’re committed.”
Dave clears his throat. The room turns.
“Last bloke who asked me to scale went bust and owed me eight thousand dollars.”
The room goes still.
“Farm-to-table scheme out of Busselton. Three years ago. Promised guaranteed orders. I expanded my planting for them. Hired a casual for harvest. They folded in August and I was out the produce, the labour costs, and the eight grand they owed me. Never saw a cent.”
He looks at Maya. Not with hostility – with the kind of frank assessment you give a stock fence before leaning on it.
“I’m here because I trust you, Maya. I trust that you grew up on a farm and you know what it costs when things go wrong. But trust doesn’t plant seeds. Contracts plant seeds. And right now, you and I have a handshake.”
Lee lets the silence sit. Then: “The assumption isn’t ‘Dave trusts us.’ It’s ‘farms will scale with us.’ And the evidence for that is a handshake and a history of being burned.”
Top-left. Firmly.
Maya writes “formalise farm contracts” on a fresh sticky note and puts it in her pocket. Dave’s words – last bloke who asked me to scale went bust – sit in the room like weather.
“We don’t have a serious competitor in Perth.”
Sam opens his laptop. “Two churned subscribers mentioned a company called Freshly. I’ve been researching.”
He walks the team through it: launched in Sydney four months ago, twelve million in Series A, ex-McKinsey founders, recruiting delivery drivers in Perth right now.
“What do they charge?” Tom asks.
“Eighteen dollars a week.”
The room does the arithmetic. Greenbox charges twenty-five.
Top-left quadrant. The team had been operating as if they were the only game in town.
Dave, from the end of the table: “Freshly rang me last week. Asking about supply. I told them I was committed elsewhere. But they’ll ring Rachel next, if they haven’t already.”
The session continues for another twenty minutes. When it’s done:
Six assumptions in the “Test Immediately” quadrant. Six things the business depends on that nobody has validated.
Designing cheap experiments
The team can’t do six research projects – they need to ship product and grow simultaneously. The experiments need to cost hours, not weeks.
“For each assumption,” Lee says, “find the smallest, cheapest experiment that would change your mind.”
Local sourcing: A survey to all active subscribers. Rank five factors. Would you consider a $20 mixed-sourcing box? The LLM helps phrase the questions to minimise leading bias. Twenty minutes to build.
Price point: Two landing page variants – current pricing alone versus current pricing with a $20 “Mixed Box” option. Track click intent for a week.
Farm scaling: Maya calls three farm partners and asks: “If we needed to double our order in three months, could you do it?”
Acquisition channel: Tom adds a mandatory “How did you hear about us?” dropdown to the sign-up flow. One hour.
Delivery cadence: Sam adds a question to the post-delivery email: weekly, fortnightly, or flexible?
Five experiments. Total cost: about eight hours. Results in one to two weeks.
The results
Local sourcing: 168 responses. Only 12% ranked local sourcing as the most important factor. Convenience dominated (38%), followed by produce quality (26%) and recipe cards (18%). 60% said they’d likely switch to a $20 mixed-sourcing box.
Maya sits with this. Sixty percent of her subscribers would accept non-local produce for a five-dollar saving. “I feel like I’ve been punched in the stomach,” she says.
Lee lets the silence sit. “It doesn’t mean local sourcing is worthless. Twelve percent rank it first – that’s twenty-four people who might leave if you drop it. But 100% local at $25 might not be the only viable model.”
Price point: 2.3x more clicks on “Subscribe” when the $20 mixed option appeared alongside the $25 local option. Having a choice made people more likely to subscribe at all.
Farm scaling: Two of three farms could increase supply by 50%. Dave – the biggest supplier – would cap out at current levels. He’d need a full growing season to expand.
Acquisition channel: Word-of-mouth: 31%. Google search: 28%. Instagram: 19%. Local press: 14%. Sam was partially right – word-of-mouth is biggest, but not dominant. Search and social together account for nearly half.
Delivery cadence: 41% wanted weekly. 35% wanted fortnightly. 24% wanted flexible. More than half wanted less frequent delivery. This explains churn the team hadn’t understood – subscribers accumulating unwanted produce and cancelling out of guilt.
The hard conversation
Maya is quiet for a long time. “I built this business around an assumption I never tested. I assumed people cared about local sourcing as much as I do. They don’t.”
“It means you have options you didn’t know you had,” Lee says. “A $20 mixed box could open up a much larger market. A fortnightly option reduces churn. Neither kills the local brand – you can still offer a premium local box for the people who value it most. But the path to 1,000 subscribers probably isn’t ‘1,000 people who care deeply about local produce.’ It’s ‘1,000 people who want dinner stress eliminated, some of whom also care about local.’”
“That’s a different business than the one I set out to build,” Maya says. She looks at Dave.
“Maybe,” Lee says. “Or maybe it’s the same business, with a broader front door.”
Dave stands up. He needs to get back before dark. He shakes Maya’s hand at the door.
“You’ll work it out,” he says. It’s not a compliment – it’s a bet. The same bet he made when he agreed to supply Greenbox on a handshake. He’s still holding.
Maya watches his ute pull out of the car park.
She thinks about his eight thousand dollars. Not a loan. A debt – the one the last bloke who asked Dave to scale left him holding when the business went under. Dave said it twice today. Once in the meeting and once in the way he shook her hand at the door. You know what it costs when things go wrong.
She does. That’s the problem.
The numbers say the premise was wrong. Not wrong wrong – 12% is real, those are real people – but it was the premise. Local at scale was the thing she was proving. If the market doesn’t want what she was proving, then she didn’t build a produce-box business. She built a vehicle for proving something nobody asked her to prove. And she got two farmers and two hundred subscribers and a handshake with Dave to sign on while she did it.
Lee is right that she has options. A mixed box, a fortnightly cadence, a broader front door – on a whiteboard, it’s obvious. She could draw the pivot in fifteen minutes. But the pivot isn’t a whiteboard. The pivot is driving back to Margaret River and telling Dave the model is changing – the exact sentence, more or less, that the last operator said before he went bust owing Dave eight thousand dollars. It’s asking two farmers who signed up for “local produce to Perth” to bet on a new story. It’s telling two hundred subscribers that what they bought is not what they’re getting. Some will stay. Some will leave. She does not know which, and she does not know how many nights between now and knowing.
And under all of that, older than all of that: her father. Who didn’t pivot either. Who held on until there was nothing to hold on to. In her family, the story of losing the farm is a story about a man who loved something too much to see it clearly. Maya has been building Greenbox partly to not be him. And today she is sitting in a car park being told that what she loves is not what the business needs her to love – and the only move that feels like the opposite of her father, the only move that isn’t holding on anyway, is to stop. Her father held on and lost the farm. The last bloke scaled and lost Dave’s eight thousand dollars. Stopping is the one thing neither of them did.
She knows, in the part of her brain that can still do arithmetic, that stopping and pivoting are not the same shape. That Dave’s eight thousand dollars gets paid back by a working business, not by an honourable wind-down. That pausing operations is still a kind of losing, just a tidier kind. But that part of her brain is tired and it is late and the drive home is long.
She thinks about the “pausing operations” email she hasn’t written yet but can feel forming at the edges of her mind, like weather moving in from the coast. Three sentences. Honest. A clean door closed. She isn’t going to write it tonight. She might not write it at all. But she can feel the shape of it now, and that frightens her more than the survey did.
When to use Assumption Mapping
- Before major investment decisions. If the team is about to spend significant time or money, map the assumptions first. The cost is trivial compared to building on a wrong assumption.
- After discovery reveals surprises. If one major assumption was wrong, others might be too.
- When the team disagrees about direction. Disagreements often hide different assumptions. Mapping makes the disagreement concrete rather than political.
When not to use it
- When the team isn’t safe enough to admit uncertainty. If admitting “I don’t have evidence” feels dangerous, the exercise produces a sanitised list. Fix the safety problem first.
- As a substitute for talking to customers. The map tells you what to test. It doesn’t do the testing.
What comes next
Maya has a board meeting in three weeks. She needs a credible path to 1,000 subscribers. The insights are powerful – mixed sourcing, fortnightly options, SEO investment. But do the numbers add up? Can Greenbox reach 1,000 with a model that works financially – especially with a competitor about to enter at $18 per week?
That’s a question about the business model itself. And it’s where Lee starts to hit the limits of what he can help with.
For that, Lee reaches for the Business Model Canvas – and Charlotte brings someone who can help with the numbers.
The next chapter, Business Model Canvas: Does This Actually Work?, publishes around 12 May.