How many customer conversations do I need before I trust the pain score?

There's no magic number. Five conversations with the right kind of person, each describing a real past episode and what they spent to deal with it, is a reasonable minimum for a first pass. If the stories keep changing, keep talking.

Why does the checklist weigh pain more than ease?

Because an easy build for a problem nobody feels produces a finished product with no buyers. Pain is weighted 0.30 and ease 0.10 so a hard but urgent problem can still outscore a simple, low-stakes one.

Can I use Google Trends as my only why-now evidence?

No. It shows relative interest over time, not absolute search volume, and attention isn't the same as purchasing. Pair it with a concrete change you can name, such as a new rule or technology, and with what buyers tell you.

What does the evidence multiplier do?

It scales the weighted total by a factor from 0.70 to 1.00. Scores backed by interviews, prices and comparables keep close to full value; scores based on opinion get discounted.

Is a low score a reason to drop the idea?

Not automatically. Look at which signal is dragging it down. A weak open-market score may mean you should narrow to an underserved group, while weak pain is much harder to fix.

Does this checklist replace talking to customers?

No. It organizes what you learn from them. Most of the points on the sheet can only be checked after real conversations.

Startup Idea Validation Checklist (Printable, 5 Signals)

A startup idea validation checklist is a short list of questions you answer with evidence before you build anything. Check five signals: is the pain real and frequent, why is now different, will someone pay, is the market open, and can you ship it. Score each one, then discount the total if your proof is thin. Below is a printable version, how to fill it in, a worked example, and the mistakes that most often inflate a score.

The printable checklist

Print this page (your browser's print dialog works fine) and fill it in by hand. Each signal has a weight. Those weights are the ones Proofline uses to score the daily idea it publishes, so the sheet mirrors how we think about it. The full reasoning is on the methodology page.

Signal	Weight	Check off only when you have this
1. Pain	0.30	☐ Named a specific person with the problem ☐ Heard them describe the last time it happened ☐ Found what they do about it today, and what it costs in money or hours ☐ Talked to at least five such people
2. Why now	0.25	☐ Can name one change (rule, technology, behavior, price) from the last few years ☐ That change makes the idea possible or urgent, and was not true before ☐ Search interest or other data points the same direction
3. Revenue	0.20	☐ Know who writes the check ☐ Found what people already pay for a workaround or rival ☐ Have a price in mind that is a small fraction of the cost of the pain
4. Open market	0.15	☐ Listed at least three real alternatives, including spreadsheets and doing nothing ☐ Written down where each one is weak ☐ Can say who is underserved by all of them
5. Ease	0.10	☐ A first version fits in a few weeks of work ☐ No permission, license or partner needed to start ☐ You can reach the first ten buyers without a big budget
Evidence multiplier	× 0.70 to 1.00	☐ Each score above rests on something you saw or heard, not something you assumed

How to fill it in, step by step

Step 1: Pain (0.30)

Pain gets the biggest weight because nothing else matters if nobody is hurting. The trick is to ask about the past, not the future. Interview guidance built on Rob Fitzpatrick's The Mom Test says hypothetical questions like "would you buy this?" get optimistic answers from people who want to be nice, so ask how they handle the problem now, what it costs them, and to walk you through the last time it came up. If they never tried to fix it, ask why not.

Score high when people have already spent time or money on an ugly workaround. Score low when they agree it's annoying and then shrug.

Step 2: Why now (0.25)

Many good ideas were simply early. Write one sentence that begins "This works now because..." If the sentence is vague, the score is low. A regulation that took effect, a new API, a platform that opened up, or a cost that dropped are all concrete. "People are more online" is not.

Google Trends can support the claim, with a caveat. It doesn't give absolute search volume; it shows interest relative to the highest point among the terms you compare, and it lets you compare two to five terms at once. Use it to see direction, not size.

Step 3: Revenue (0.20)

Find the money that already moves. Look for a paid tool, a freelancer, a staff hour, a fine or a lost job that your idea replaces. Then ask for a commitment that costs something: a deposit, a signed letter of intent, a pre-order. A kind word costs nothing and tells you nothing.

Step 4: Open market (0.15)

List competitors honestly. A common failure is claiming there are none, or listing big generic tools that don't actually serve your buyer. ValidatorAI's own checklist makes the same point: for each competitor, note what they do, their pricing, positioning, strengths, weaknesses and the gaps they leave. "Open" doesn't mean empty. It means you can name a group of buyers the existing options handle badly.

Step 5: Ease (0.10)

Ease carries the smallest weight on purpose. A hard idea with severe pain still beats an easy idea nobody wants. But ease decides whether you learn anything this quarter, so don't skip it.

Step 6: Apply the evidence multiplier

Proofline multiplies the weighted total by a factor between 0.70 and 1.00 depending on how much evidence sits behind the scores. You can do a rough version by hand: 1.00 if you have interviews, prices and comparables written down; closer to 0.70 if the scores are mostly your own opinion.

A worked example

Say you're looking at scheduling software for a narrow trade. Score each signal from 0 to 10 and multiply by its weight.

Signal	Score	Weight	Points
Pain	7	0.30	2.10
Why now	5	0.25	1.25
Revenue	6	0.20	1.20
Open market	4	0.15	0.60
Ease	8	0.10	0.80
Subtotal			5.95
Evidence multiplier			× 0.85
Result			5.06

These numbers are made up to show the arithmetic. They aren't a real idea's score. The point is the shape: strong pain and ease can't fully cover a mediocre why-now and a crowded field, and the multiplier takes another bite when proof is partial. If you want to see the format applied to real ideas with comparables, browse today's idea, the idea archive or the leaderboard.

Mistakes that inflate scores

Interviewing friends. They want you to feel good. Talk to strangers who have the problem.
Pitching during the interview. Once you mention your idea, answers bend toward it. Keep the conversation on their life.
Treating a trend line as demand. Rising search interest shows attention, not willingness to pay.
Counting only software competitors. The real rival is often a spreadsheet, a part-time assistant or a habit.
Scoring ease first. It's the most fun to score and the least predictive.
Never writing evidence down. If you can't point to a note, a quote or a link, the multiplier should drop.

Where other checklists do better

This sheet doesn't ask whether you are the right founder. ValidatorAI's checklist includes a founder-problem fit step, covering skills, network, lived pain and access, and that's a fair thing to weigh, especially if you'll be selling to a niche you don't know. Their checklist is also 10 steps and runs through prompts, so if you want a longer, more guided process it may suit you better. See our ValidatorAI comparison for more. If you'd rather start from a market than a hunch, the category pages for trucking, restaurants and real estate list ideas already scored.

Startup Idea Validation Checklist: A Printable Sheet Built on Five Signals