Why Nobody Buys Your Product: The Milkshake Theory That Changed Everything

1. The Accelerator That Nobody Wanted

In 2019, my co-founder and I built what we believed was the best startup accelerator in Taiwan. I'm not exaggerating for effect — I genuinely believe we had the right people, the right curriculum, the right mentors, and the right network. We had spent years in the startup ecosystem. We knew what founders needed. We were going to give it to them.

The program ran. Cohorts came through. But something was always slightly off. The engagement wasn't what we expected. The satisfaction scores were decent but not excited. Founders completed the program and then... drifted. They didn't stay connected. They didn't refer their friends. They didn't come back for the alumni community we'd built for them.

We kept iterating. Better guest speakers. Tighter curriculum. More networking events. A Slack community. A newsletter. Each change helped a little. None of them fixed the fundamental problem.

It took me years — and a lot of money — to finally understand what we were doing wrong. And the understanding came not from a consultant, not from a pivot workshop, not from more market research. It came from a story about milkshakes.

2. The Milkshake Story: How Christensen Changed Marketing Forever

Clayton Christensen was a Harvard Business School professor and one of the most influential management thinkers of the last half-century. He wrote The Innovator's Dilemma, which changed how the world thinks about disruptive technology. But the story that changed how I think about business wasn't about disruption — it was about milkshakes.

McDonald's had a problem: milkshake sales were flat, and traditional market research wasn't helping. They asked customers what would make the milkshakes better. Customers said: make them sweeter, offer more flavors, make them thicker. McDonald's tried those things. Sales didn't meaningfully improve.

Christensen's team took a different approach. Instead of asking what customers wanted, they asked: when are milkshakes bought, by whom, under what circumstances, and for what purpose?

What they found was striking. Before 8am, roughly 40% of milkshake purchases were made by a single demographic: solo commuters, almost always in work clothes, almost always in a hurry, almost always buying nothing else. They weren't buying a dessert. They weren't buying a sweet treat to enjoy with lunch. They were buying something to do for the next 90 minutes of boring highway driving — something they could sip slowly through a straw, that would keep their hands occupied and their hunger at bay until they reached the office.

Christensen called this Jobs-to-be-Done (JTBD) — the idea that people don't buy products. They "hire" products and services to do a specific job for them. Understand the job, and you understand what your product actually competes with, who actually wants it, and how to make it irreplaceable.

This sounds obvious when you read it. It is anything but obvious when you're in the middle of building something you believe in.

3. The Wrong Job: What iiinno Was Actually Selling

When I finally encountered JTBD properly — not as a concept I'd skimmed in a business book, but as a framework I actually applied to my own situation — I went back and looked at iiinno with fresh eyes. What job were founders hiring us to do?

We thought we knew. Founders hire accelerators to build better startups. To get mentorship, funding connections, and product feedback. To accelerate their journey from idea to market.

That's not wrong, exactly. But it's surface-level. When I looked more carefully at the moments where our founders were most energized — not most satisfied with the curriculum, but genuinely lit up — I started to see something different.

They were energized when they met someone who shared their problem. When they realized "that person is struggling with the exact same thing I am, and she's two steps ahead." When they had a mentor look them in the eye and say: "I've been exactly where you are. Here's what I did."

They weren't hiring us to learn startup methodology. They were hiring us to not feel alone. To get permission, from people who'd done it, that their crazy idea wasn't actually crazy. To find a tribe of people who understood the particular loneliness of trying to build something new in a society that values stability over risk.

That's a completely different job. And it requires a completely different product.

Our curriculum — which was genuinely excellent — was solving the wrong job. A founder who is terrified and isolated doesn't first need a better pitch deck. They need to know that someone like them has survived this, that the path forward is real, that they are not alone in the dark.

We had built an educational product when they needed a belonging product. And no amount of better curriculum was going to fix that.

4. Three Taiwan Examples That Make JTBD Click

Let me bring this closer to home. Three examples from Taiwan that show how Jobs-to-be-Done plays out in markets most people look at and get completely wrong:

In each case, the product that dominated its market did so not because it was objectively superior on the most obvious dimension, but because it solved the real underlying job better than the alternatives. Features matter second. Job match matters first.

5. The Gap Is Where the Money Is

Here's the simplest way I've found to explain JTBD to someone in under two minutes:

The customer has a current state — the situation they're in right now. They have a desired outcome — where they want to be. The distance between the two is the job to be done. That's where your product should live.

The mistake most builders make is focusing entirely on what their product does (features, capabilities, specs) rather than on the gap it crosses. A customer doesn't buy a drill because they want a drill. They buy a drill because they want a hole in the wall so they can hang a picture so their new apartment feels like home. The job is "make this place feel like home." The drill is just the mechanism.

When you identify the real job, three things happen:

1. Your positioning becomes clearer — because you're describing a struggle the customer already knows they have
2. Your competition changes — you're no longer competing with everyone who sells the same product, but with everyone who solves the same job (including doing nothing)
3. Your product decisions simplify — you stop adding features nobody asked for and start making the core job cheaper, easier, and more satisfying to complete

6. How JTBD Saved Coastline's Positioning

When I started building Coastline in early 2026, I had already learned the iiinno lesson the hard way. I was determined not to repeat it. So before I wrote a single piece of content, before I built a single page, I did the job mapping exercise.

I asked: who am I building this for, and what job are they actually trying to get done?

My first instinct was: "I'm building for people who want to improve their relationships and build better businesses." That's true but useless. It's the drill answer, not the home answer.

I went deeper. I thought about the people in my LINE communities. The ones who kept coming back. The ones who sent me voice messages at 11pm because something I said had unlocked something for them. What were they actually struggling with?

They weren't struggling to learn frameworks. They were struggling with a specific, painful question that nobody in their life was helping them answer: Why do I keep doing everything right and still feel like nothing is working?

They were working hard. Being kind. Being responsible. Following all the rules they'd been told would lead to a good life. And yet: depleted relationships, businesses that weren't growing, a sense of profound disconnection between effort and outcome. They needed someone who had been there — who had the same good intentions and the same painful results — to help them see what they were missing.

That's the real job Coastline does. Not "learn frameworks." Not "improve relationships." Not even "build a better business." The real job is: figure out why the life you're working so hard to build keeps not materializing, and what to actually do about it.

Once I understood that job, everything about Coastline's positioning became clearer. The blog posts started with personal failure, not professional advice. The newsletter was honest about what I was still figuring out. The e-book was built around three elements that address the actual sources of the gap — not just tactics, but the underlying operating system.

And the response was completely different from iiinno. Not because the content was better written. Because it was solving the right job.

7. How to Find the Real Job Your Customers Need Done

Here's the practical process I use now before building anything new:

Step 1: Interview buyers, not prospects. Talk to people who already bought from you or something similar. Don't ask what features they liked — ask what made them finally decide to buy. What was happening in their life at that moment? What else did they consider? What had they tried before? The decision context is where the real job lives.

Step 2: Interview the people who quit. Talk to people who started the buying journey but stopped. They'll tell you — if you ask directly — what job your product failed to solve. This is some of the most valuable data you can collect, and almost nobody collects it.

Step 3: Watch the timeline. Map what your customer does before and after they interact with your product. What triggers the need? What do they do immediately after? Christensen's team didn't just survey milkshake customers — they watched them buy, watched them consume, and watched what happened next. The commute revelation came from observation, not survey data.

Step 4: Ask "why" five more times than feels comfortable. When someone says "I wanted better productivity," ask why that mattered to them. When they answer, ask why again. By the fourth or fifth why, you usually hit something true and specific and human — something that sounds less like a product requirement and more like a confession. That's where the real job lives.

Step 5: Write the job story. Fill in this sentence: "When [situation], I want to [motivation], so I can [desired outcome]." For iiinno, the real job story would have been: "When I'm building a startup and feeling terrified and isolated, I want to find people who've survived this and stayed sane, so I can believe that I can too." Once you can write that sentence clearly, you have your north star.

8. Start Here: Three Questions for This Week

I know the temptation when you read something like this is to understand it intellectually and then not actually change anything. I've done that myself, more times than I can count. Understand the theory, nod along, go back to building the same product the same way.

So here's the smallest possible version of doing this work. Three questions. This week. Before you build or launch or iterate anything else:

1. What job are customers actually hiring your product to do right now? Not what you designed it to do — what are they actually using it for? These are often not the same thing. Christensen found that some McDonald's customers hired the morning milkshake for the same job at lunch — keeping their kids busy at the table — and for that job, smaller and faster was better, not thicker and slower. Same product, same category, completely different job.
2. Who is your real competition? If you're clear on the job, you can answer this. Coastline's real competition isn't other business blogs. It's the internal voice that tells my reader to "just keep doing what you're doing, it'll work out eventually." My product competes with denial. Knowing that changes how I write every post.
3. What would make this job impossible not to hire you for? Once you know the real job, you can optimize directly for it. Not "better features." Better job fit. The milkshake that solves the commute job needs to be slow to consume, easy to hold, and available at 7:30am. You're not competing on sweetness anymore — you're competing on perfect job execution.

My first startup failure was building and then finding customers. My second attempt — iiinno — was finding customers and then building the wrong product because I never understood their actual job. Coastline is the version where I did the job mapping first. The difference in response has been significant.

You already know your product is good. The question is whether it's good at the right thing. Find the job first. Then build.