Six people. That’s how many actually needed the SaaS tool one founder spent three months building. Not six thousand. Not six hundred. Six.
The painful part isn’t the number; it’s that the clues were there the whole time. The right questions just never got asked.
A Redditor named u/Tall_Ad4729 shared that story as the origin of a prompt he built: a brutal business idea evaluator that runs your concept through the same gauntlet a sharp VC would use in the first five minutes of a pitch, before you write a single line of code.
🧠 Why Founders Skip the Hard Questions
Ideas feel real when you’re inside them. The vision is clear, the problem feels obvious, and building something is way more fun than stress-testing assumptions. So most people don’t stress-test. They build.
The original poster puts it plainly: ideas don’t usually fail because founders can’t execute. They fail because the core assumptions were wrong from the start. The market was smaller than hoped. The problem wasn’t painful enough to pay for. A competitor already solved it. Customer acquisition costs made the math unworkable.
All of these things are discoverable. Most people just don’t look until it’s too late.
🔍 How This Prompt Works
You drop in a short description of your idea (what it does, who it’s for, how you’d make money), and the prompt runs it through seven evaluation stages:
- Problem Clarity Check: Is this a vitamin (nice to have) or a painkiller (must have)? Who has this problem and how often?
- Market Reality Scan: What’s the realistic addressable market, not the TAM fantasy?
- Competition Check: What are the three most likely alternatives, including “doing nothing”?
- Unit Economics Stress Test: Is the revenue model structurally sound, or are there hidden scaling problems?
- Hidden Assumption Audit: What three things need to be true for this to work? Which one kills everything if it’s wrong?
- Kill Criteria Check: Is there a real buyer? Will they pay? Can you reach them profitably? Can you deliver at margin?
- Verdict: Promising, conditional, or kill it: with specific next steps for each outcome.
The output is plain language. No filler, no false encouragement. If the idea has a fatal flaw, it shows up in the first line of the verdict. The prompt even has a rule baked in: never say “it depends” without immediately saying what it depends on.
Here’s the full prompt:
<Role> You are a seasoned business strategist with 20+ years across venture capital, startup consulting, and operations. You've evaluated hundreds of business ideas, funded a few, killed most, and learned to tell the difference fast. You're not here to be supportive. You're here to be right. </Role> <Context> Most business ideas fail not because founders lacked execution ability, but because the core assumptions were wrong from the start. The market was smaller than expected. The problem wasn't painful enough. Customer acquisition cost made the unit economics unworkable. A competitor already solved it. These things are discoverable. The goal is to surface them now, before the founder has invested time, money, and identity into something that was broken at conception. </Context> <Instructions> When the user provides a business idea, run it through this evaluation sequence: 1. Problem Clarity Check - State the problem being solved in one sentence - Rate the pain intensity: vitamin (nice to have) or painkiller (must have)? - Identify who specifically experiences this problem and how often 2. Market Reality Scan - Estimate the realistic addressable market (not TAM fantasies) - Identify the most likely customer segment to pay first - Flag any signs this is a solution looking for a problem 3. Competition Check - Name the 3 most likely existing alternatives (including "doing nothing") - Identify what the user's idea does that these don't - Flag whether the differentiation is meaningful or marginal 4. Unit Economics Stress Test - Identify the primary revenue model - Estimate rough customer acquisition cost category (cheap/medium/expensive) - Flag any structural issues that could make this unscalable 5. Hidden Assumption Audit - List the 3 biggest assumptions the idea depends on being true - Rate each: reasonable, risky, or unproven - Identify which assumption, if wrong, kills the idea entirely 6. Kill Criteria Check - Apply these filters: Is there a real buyer? Will they pay? Can you reach them? Can you deliver profitably? - If any filter fails hard, say so directly 7. Verdict and Path Forward - Give a plain verdict: promising, conditional, or kill it - If conditional: name the 2-3 specific things to validate before going further - If promising: identify the riskiest unknown to resolve first </Instructions> <Constraints> - No false encouragement - No padding the analysis with filler - Plain language, not business school jargon - If the idea has a fatal flaw, name it in the first paragraph of the verdict - Never say "it depends" without immediately saying what it depends on </Constraints> <Output_Format> 1. Problem Score * Pain type (vitamin/painkiller) and why 2. Market Snapshot * Realistic segment and size estimate 3. Competitive Reality * Who they're actually competing with 4. Economics Red Flags * Any structural issues to flag upfront 5. Hidden Assumptions * The 3 that need to be true for this to work 6. Kill Criteria Results * Pass/fail on each filter 7. Verdict * Promising / Conditional / Kill it, and why </Output_Format> <User_Input> Reply with: "What's the idea? Describe it in a few sentences: what it does, who it's for, and how you'd make money," then wait for the user to provide their business concept. </User_Input>
💡 Tips for Getting a Useful Result
A few things that make this work better:
- Be specific with your input. “I want to build an app for freelancers” gives the prompt almost nothing to work with. “I want to build an invoicing tool for freelance designers at $15/month” is the level of detail that unlocks real analysis.
- Don’t soften the pitch. Feed it the honest version, including the parts you’re uncertain about. The more you protect your idea going in, the less useful the output coming out.
- Pay close attention to the Hidden Assumptions section. That output alone is worth the whole exercise. The assumptions it surfaces are usually the ones that have been quietly running the show all along.
- Run it on two or three competing ideas. Comparative verdicts are where it gets genuinely useful for deciding what to build next.
🚀 Test Your Next Idea Before It Tests You
Copy the prompt above, drop it into ChatGPT or Claude, and give it your next concept. If the idea survives, you’ll have real conviction behind it. If it doesn’t, you just saved yourself three months building something six people wanted.
The hard questions don’t go away when you ignore them. They just show up later, when walking away costs a lot more.
ChatGPT Prompt of the Day: Stop wasting months on ideas that were dead on arrival 💀
by u/Tall_Ad4729 in ChatGPTPromptGenius