Before You Build More: Walk Through One Customer’s Day
When you’re building something new, everyone tells you to “define your ICP.” Most of the time that means big frameworks, pitch deck language, and sometimes assumptions about scaling and fundraising. If you’re a serious builder working on a ‘right‑sized’ venture, that’s probably not what you need first. You just need to know whether your product actually fits into one real person’s day.
Over the years I’ve used all the usual tools – empathy maps, personas, customer journey maps, the whole nine yards! They can be really valuable, especially when you’re deep in a big team project or a funded startup, that depth of mapping can really help with complexity and multiple stakeholders.
But if you’re a solo or small‑team builder working on a right‑sized venture, you don’t always need to go really deep, and you don’t need a big workshop. Sometimes you just need something light, human and impactful that you can do in under an hour and still walk away seeing your customer more clearly.
That’s what One Customer, One Day is for - a small exercise to walk through one real customer’s life and find the moment your new product belongs. This is easy to just get started, all you really need is a conversation with a potential customer, a notebook, and an honest look at how someone actually lives and works.
“One customer, one day” – Fitness/wellness version
OK, let’s get practical and use an example story - say you’re building something for independent Pilates and yoga instructors.
Meet Sara (your ‘right‑fit’ customer)
You don’t need a full persona deck. Just this:
Sara runs small group Pilates classes and a few 1:1s.
She works out of a shared studio, teaches 4–5 sessions a day, and does all the admin herself.
Tech stack: Google Calendar, a spreadsheet, WhatsApp and Stripe links she sends manually.
Sara’s day (very roughly)
07:30 – Checks WhatsApp, a mix of “can I switch to tonight?” and “is there space on Wednesday?”
09:00–12:00 – Morning classes, mentally tracking who has actually paid.
12:30 – Grabs lunch, updates a spreadsheet with attendance, chases one missed payment.
15:00–18:30 – More classes and 1:1s, more WhatsApp juggling for last‑minute changes.
20:00 – On the sofa, sending Stripe links and replying to “can I pause my membership?”
When you look at this schedule, nothing here screams “I need a full studio management platform.” But what you can see is that there are a few obvious friction points.
What Sara is using now
Bookings: “DM me to book” plus a manually updated Google Calendar.
Payments: Stripe link templates in her Notes app.
Communication: 100% WhatsApp and Instagram DMs. Sometimes Messages on her iPhone.
Tracking: A messy spreadsheet with tabs for “active,” “paused,” and “owe me.”
Her real “system” here is habit + memory + a few digital scraps.
Where your micro‑SaaS or tool might fit
Instead of “all‑in‑one platform for fitness businesses,” your right‑sized product might be:
“A simple class list + payments tracker that sits between WhatsApp and Stripe.”
In “One customer, one day” terms:
It shows up at two moments:
When she checks who’s coming to tonight’s class.
When she sits down in the evening to check who’s paid.
Switching cost must be near‑zero:
Import contacts from her phone, keep using WhatsApp, but have one place that knows who’s booked and who’s paid.
The useful clarity from this story
From a single day in Sara’s life, a serious builder can see:
They’re not competing with big SaaS products; they’re competing with “WhatsApp + spreadsheet + habit.”
Features that don’t obviously reduce that evening admin (complex marketing automation, multi‑location support, etc.) - all of that can wait.
Messaging should sound more like this:
“For solo Pilates / yoga instructors who are tired of chasing who’s booked and who’s paid,”
not “All‑in‑one platform for boutique studios.”
This is exactly the kind of human‑level clarity One customer, one day should unlock. Because when you walk through Sara’s day like this, you notice two things: first, how much she’s already juggling with the tools she has; and second, how small a product needs to genuinely helpful. In this example, you can easily see that you don’t need ‘a platform’, but a clear moment where you make life easier than her current workaround.
One Customer, One Day is a way to find that moment for your own idea.
It won’t give you a big deck that you might not even look at again; it will give you a sharper picture of who you’re really building for, what you’re asking them to change and whether your product actually ‘earns’ a place in their day.
If that picture throws up more questions than answers, that’s usually the signal you’re ready for a thinking partner helping you gain more clarity and make confident decisions – and that’s where The Next Move comes in.