There is no threshold. I know that is the answer nobody wants and it is the true one, so the rest of this is about what to use instead.
The reason a universal number cannot exist is that the same count means opposite things depending on four variables, and any benchmark you find on the internet is silent about all four.
Why the number is unanswerable as asked
Four hundred signups from a post that did well in one community tells you about that community. It may not survive contact with anyone outside it.
Four hundred from cold search is a much stronger signal, because those people had a problem and went looking.
Four hundred unverified might be two hundred and forty people. You cannot know.
Four hundred for a $9 consumer tool is a different fact from four hundred for a $2,000-a-year enterprise product, where forty of the right ones would be a company.
So the count on its own is uninterpretable. Four numbers make it interpretable.
The four numbers that replace it
1. Verified fraction. Of everyone who signed up, how many confirmed an email? Below about two-thirds, look at your traffic source before anything else — you are likely counting a lot of things that are not people. Double opt-in is free on every Osokoro plan, including the free one, precisely because a count you cannot trust is worse than no count.
2. Source concentration. What share came from your single best source? If one post is 80% of your list, you have validated a post. Repeatable acquisition is a separate question and the more dangerous one, because it is the one that kills companies after they build the thing people wanted.
3. Answer rate on the free-text question. Of verified signups, how many wrote something real when asked what they do today? This is the rate I would watch above all others. People who type two sentences about their own situation are qualitatively different from people who typed an address, and the ratio between them tells you how much of your list is interested rather than idle.
4. Reply rate to a real email. Send something genuine three weeks in. Count replies, not opens. This is the strongest signal a waitlist can produce and almost nobody collects it, because it requires sending something and risking the answer.
A list of 150 with 80% verified, three sources, 40% writing real answers, and thirty replies is worth more than 2,000 from one viral post with none of the above. Comfortably.
Set the bar before you can move it
The failure mode here is not choosing a wrong number. It is choosing the number after seeing the result, at which point it is not a bar, it is a rationalisation.
Write both sentences down before you launch the page:
If ___, I build. If ___, I stop.
If the second is empty, you are collecting encouragement rather than evidence — a legitimate thing to want, and not this.
A reasonable shape for a small software product: sixty verified signups, from at least three sources, of whom twenty-five describe the problem in a way I recognise, and ten reply to an email. Those are made-up numbers and the shape is the point — a count, a diversity condition, a quality condition, and an effort condition. Pick your own values. Pick them now.
The arithmetic nobody does
Work out how many signups your business needs, rather than how many feel reassuring.
signups needed = target customers
÷ signup-to-paying conversion
You do not know the conversion rate. Nobody does before launching. But bracketing it is still useful: at 2% you need fifty signups per customer, at 10% you need ten. If you need a hundred paying customers to be viable and you think 5% is optimistic, that is two thousand signups — and if you have four hundred after two months of your best channels, the arithmetic is telling you something about acquisition long before it tells you anything about demand.
That is usually the more valuable finding, and the count alone will never surface it.
Small numbers that are actually good
Some situations where a small list is a strong result:
- Expensive B2B. Twenty signups from twenty companies who each have the problem is a pipeline.
- A narrow professional niche. If the total population is four thousand, a hundred is 2.5% of the world.
- No promotion at all. Forty signups from nothing but a page and word of mouth is a different fact from forty after a launch push.
And the inverse: a large list from a single viral moment is the most over-read result there is. Those people signed up because the post was good. Many will not remember you in a month, which you can verify cheaply by writing to them and counting replies.
What no count settles
Whether you can build it. Whether you can reach these people repeatably at a price that works. Whether they still want it in six months. Whether the interest survives a price.
A signup is one person's zero-cost decision at one moment. Even a lot of them stay that. The count is the beginning of the question, and the four numbers above are the part that answers it.