I show the above slide because it gets a laugh — whether for a five-week sprint or an afternoon workshop. After all, Back to the Future is a good movie — often cited as one of the most perfect beat-by-beat screenplays in American filmmaking. But also because time is one of the few things humans cannot influence. Definitely can't control.
I tell them our time together is going to fly by. It's going to feel like there's not enough time and that's intentional. Because when time is constrained in this way, we don't have time to beat around the bush. We find what actually matters.
And here's what I've learned after running Bullseye Customer Sprints for the past year: the timeboxing isn't just about efficiency. It's a forcing function that prevents something much more expensive than wasted time.
The real cost of 182 1/2 days
Most founders spend six (6) months "validating their idea" or looking for product-market fit — which really means:
Dreaming up a feature set that would be worth bragging about
Building elaborate personas based on assumptions
Analyzing competitor positioning instead of talking to actual humans
Doing a variety of activities (often random) to confirm what you already believe
Having long internal debates about who the customer might be
All while building, shipping, and growing. They may or may not discover that they built for themselves. Or for someone who doesn't exist.
Here's what those six (6) months actually cost:
Wasted payroll: Your team spent half a year building features nobody asked for. At a small startup with 3-5 people, that's $150K-$300K in salary building in the dark.
Scattered marketing: You can't clearly explain who you're for, so your messaging tries to appeal to everyone. Your customer acquisition cost (CAC) climbs because you're not speaking directly to anyone.
Inconsistent sales: Pipeline is unpredictable. Some months you close deals, other months nothing. Sales/customer success can't articulate why someone should choose you over alternatives.
Climbing churn: Customers who do buy often leave quickly because they misunderstood what you do. They bought for the wrong reasons.
Stalled fundraising: Investors ask "who's your customer?" and everyone on your team gives a different answer. Or worse, you list a plethora of different types because you can't commit.
Strategic risk: You're six (6) months closer to running out of runway with no validated direction. Every week without customer evidence compounds the risk of building the wrong thing.
The problem isn't that you don't want customer evidence. It's that without a forcing function of validating who the customer is plus their goals and pains, the business is essentially an endless hamster wheel.
Without a forcing function to validate your customer, building a product can feel like an endless hamster wheel — lots of motion, no forward progress
The Bullseye Customer Sprint is five (5) weeks total:
Wk 1: Hypothesis generation — align on who you think your bullseye customer is, what triggers their need, what disqualifies someone. Document your assumptions before you talk to anyone.
Wk 2: Create prototypes — build 2-3 simple prototypes showing different value propositions. Just enough to test assumptions in conversations. Not production-ready. Not pixel-perfect. Good enough to learn.
Wk 3: Five (5) customer interviews over Tue, Wed, and Thu — same week. Each interview is an hour-long: half customer context, half testing assumptions. Your whole team observes live and debriefs immediately while it's fresh.
Wks 4-5: Document positioning — consolidate learnings. Refine your customer definition based on what you heard. Document why customers choose you over alternatives. Create your action plan.
Time commitment: 2-3 hours per week from core team, plus the five (5) interviews. About 40 hours total over five (5) weeks.
How time scarcity changes your thinking
Give a team a vague time horizon for some task, like defining their customer, and they'll spend a few months debating edge cases and building elaborate personas based on guesses. Each person on the team will have a different version of who the customer is in their head.
With five (5) weeks, you’re forcing a different kind of thinking. The constraint forces alignment twice: once before you talk to customers and once after.
In the first week, everyone documents what they believe. Your PM thinks the customer is technical. Your designer thinks they're working on-the-go. Your founder thinks the cost is most important thing. But you can't move forward until you write it down and agree on what you're testing.
Then, the third week reveals where you were all wrong. Your whole team watches the same bullseye customer interviews. Hears the same stories. Sees the same patterns. At the end of the third day of interviews, nobody's arguing about opinions anymore because you all witnessed the same evidence.
This is how constraint changes the quality of thinking, not just the speed:
It forces prioritization — you can't ask everything, so you have to decide what questions actually matter. What will change your product roadmap? What will help you say no to the wrong customers?
It forces observation over opinion — when you only have five (5) interviews, you can't afford to miss what people are actually saying. You stop filtering their words through your assumptions.
It forces team alignment twice — wk1: everyone documents their hypothesis. Wk 3: everyone watches the evidence. The contrast between what you expected and what you heard creates clarity that months of internal debate never could.
It limits the damage — five (5) weeks is short enough that if your first hypothesis is wrong, you haven't burned six (6) months of runway. You revise and run another sprint. Or run a month of additional customer interviews to get clear and find the evidence.
What you get
After the sprint, you have:
A documented bullseye customer definition that's narrow and specific enough to make decisions
Evidence about which value propositions in the prototype resonate and which fall flat
Quotes from actual customers explaining their triggers and your competition
Internal alignment because everyone heard the same five (5) conversations
Confidence to make product, marketing, and sales decisions based on patterns, not guesses
You won't know everything about your market. But you'll know enough to make informed decisions about who adopts first and why — not guesses, evidence.
Want the detailed breakdown?
Reply to this email and I'll send you the three-page Bullseye Customer Sprint PDF covering the full process, hypothesis generation, interview structure, and FAQs.
Something else to consider
"You don't have time to be wrong about your assumptions. What are your key assumptions? What if they're all wrong? How much work would you have to redo? How long would that take?"
Erika's questions cut through the "we don't have time for research" objection by reframing what you're actually risking. It's not about whether you have time to validate your assumptions. It's about whether you can afford to spend six (6) months building on assumptions that might be completely wrong.
The five-week sprint doesn't just compress timeline. It forces you to name your assumptions in the first week, then test them in the third week before you've invested too much in being wrong. Every week you spend theorizing instead of observing is a week you're compounding potential rework.
And after the sprint? Teresa Torres advocates for shorter, more frequent customer interviews — 15-30 minute sessions conducted weekly — to maintain continuous discovery. The sprint gets you oriented quickly. Weekly conversations keep you oriented as you build.
There's no such thing as time management. Time just moves. What you actually manage is focus — and how much damage you allow before you check your thinking against reality.
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Until next time,
Skipper Chong Warson
Making product strategy and design work more human — and impactful
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Book a 25-minute intro call with us — we'll discuss what you're trying to figure out, whether you have customer access, and if the sprint timeline works for your stage.