Jeremy King: Startup Story, Funding & Lessons (2026)

Before Jeremy King raised over $104 million for his B2C insights platform, Attest, he didn’t write a line of code. He didn’t build a fancy MVP or hire a team. He went to a London train station with a pen and a clipboard and started asking questions.

His story cuts through the noise about what the 'hard part' of starting a company really is. It’s not incorporating, finding an accountant, or opening a bank account. Those are administrative tasks you can solve for a few hundred dollars.

The truly hard part is overcoming the inertia of a comfortable career to test an unproven belief. It’s making the leap—not with blind faith, but with evidence. King’s pre-launch validation provides a powerful, low-cost playbook for any founder looking to de-risk their idea before going all-in.

The Pre-Leap Validation Playbook: The 'Clipboard Test'

King, then a consultant at McKinsey with a fresh Harvard MBA, believed B2C companies were starved for high-quality, real-time consumer data. But a belief isn’t a business. He needed to prove it.

Step 1: Identify the Problem Owner

Your first job is to find the person whose professional life is directly impacted by the problem you think you can solve. King didn’t email a corporate headquarters. He went to the front lines: a busy London train station.

He approached the managers of two different retail stores. These were the people responsible for daily sales targets, inventory, and marketing effectiveness. They lived the problem every day.

Actionable Advice: Don’t theorize about your customer. Find them in their 'native habitat.' If you’re building for developers, go to GitHub or a developer meetup. If you’re building for restaurant owners, walk into restaurants on a Tuesday morning.

Step 2: Ask What They Don’t Know

King asked a simple but brilliant question: “What don’t you know about the people passing through this station?”

This is the opposite of a sales pitch. It’s an invitation to reveal pain. The store managers immediately opened up:

Why don’t more of the thousands of people walking by come into our store? · Of the people who do come in, why don’t they buy? · What do people passing through actually want to buy, versus what head office sends us?

When King asked what they were currently doing to solve this, their answer was, essentially, nothing. They just hoped for the best. This is the signal of a massive opportunity: a clear, acknowledged pain with no existing, accessible solution.

Step 3: Manually Build the Solution

Instead of promising a future software platform, King became the platform himself. He took his clipboard, stood in the station, and surveyed about 100 passers-by, asking the very questions the managers wanted answers to.

Over a single weekend, he compiled the raw data into a simple report. He didn't need algorithms or dashboards. He just needed to synthesize the answers into actionable insights the managers could use to hit their quarterly targets.

Step 4: Deliver the 'Product' and Measure the Reaction

King returned to the store managers with his hand-crafted report. Their reaction wasn't polite interest; it was excitement. He had delivered tangible value that directly addressed their biggest professional anxieties. He had given them a new tool to win.

This excitement was the single most important piece of validation. It proved someone would find his data valuable. This manual, human-powered loop became the foundation for Attest, a company now valued in the hundreds of millions.

Common Founder Mistakes in Idea Validation

King’s approach worked because it avoided the common traps that lead founders astray.

Mistake 1: Pitching Your Solution, Not Exploring Their Problem

Most founders start by saying, “I’m building an app that does X, would you use it?” This is a leading question that invites polite agreement, not honest feedback. Ask open-ended questions about their workflow and frustrations, like King did.

Mistake 2: Fearing the 'Unscalable'

Founders obsess over scalability from day one. But the goal of validation isn’t to build a system for 10,000 customers; it’s to prove one customer has a desperate need. Doing things that don't scale—like manual data collection—is the fastest way to learn.

Mistake 3: Mistaking Politeness for Purchase Intent

Friends, family, and even friendly strangers will tell you your idea is “interesting” or “cool.” This is worthless feedback. Real validation is an emotional reaction. It sounds like:

“When can I have this?” · “How much does it cost?” · “Can you do this for my other five stores?”

The store managers' excitement was an authentic signal of demand.

A Framework for 'Burning the Bridges'

For King, the biggest barrier wasn't the idea; it was leaving a prestigious, high-paying job at McKinsey. He was encouraged by mentors to “burn the bridges” and go all-in, because anyone you hire or ask for investment will expect nothing less.

But this doesn't mean leaping blindly. Your goal is to build up evidence-based conviction . Before you quit your job, ask yourself:

Problem-Owner Identified: Do you know the specific job title of the person who feels the pain you’re solving? · Pain Confirmed: Have you interviewed at least 20 of these people and heard them describe the problem in their own words, without your prompting? · Manual Solution Delivered: Have you delivered a 'clipboard' version of your solution to at least 5 of them? · Excitement Measured: Did they react with genuine excitement and ask for more, or just polite interest? · Willingness-to-Pay Tested: Did you ask if they would pay for this? For example: 'If I could provide this report weekly, would it be worth $200/month to you?' The specific answer matters less than their reaction to being asked for money.

If you can’t check these boxes, you don’t have enough evidence to quit your job. Keep testing.

From Validation to a $104M Fundraising Narrative

This rigorous pre-launch validation doesn't just de-risk your own leap; it becomes the cornerstone of your fundraising story. When you can walk into an investor meeting and say:

“I identified a critical unknown for retail managers. I manually gathered the data they needed and delivered it. They were so excited they asked how to get it every week. I have a list of 10 managers who want to pay for this service the moment it’s ready. My co-founder and I are the right team to build the scalable version of what I’ve already proven people want.”

That is an infinitely more powerful pitch than a deck full of market-size numbers and unproven assumptions. You have replaced speculation with facts. This is how you build a compelling narrative that can attract over $100 million in capital and build a team of 160 people, just as Jeremy King did.

How to Apply This a Week

Write down your core assumption. (e.g., 'E-commerce marketers struggle to generate creative ad copy.') · Identify the problem-owner. (e.g., 'Performance Marketer at a DTC brand with $1M-$10M in revenue.') · Find 5 of them. Use LinkedIn, Twitter, or your personal network. · Ask for 15 minutes of their time to discuss their workflow. Do not pitch your idea. · Ask them open-ended questions. 'What's the most frustrating part of your week?' 'What takes up the most time in your ad creation process?' 'What do you wish you had a better handle on?' · Listen. The future of your startup is in their answers.