How many waiting list signups should we have before building MVP?

I run a viral waitlist tool (https://getlaunchlist.com) to collect email addresses and find early users.

I have seen websites with more than 1K users on the waitlist, but the conversion rate is pretty low when they invite their users on launch day.
It's because people lose interest in your product or completely forget about it in 2-3 months. The best way is to build your product as soon as possible and not rely completely on the waitlist users to convert. Another thing you can do is to regularly update waitlist users about your progress and ask for feedback/suggestions so they won't forget you.

Also, if your waitlist users are sharing your website in exchange for rewards (discounts) or early access then these users are genuinely interested in your product. If you can find 10-50 (depending upon your niche/industry) genuinely interested users then your idea is already validated.

I've wondered this too before and haven't come up with a clear number. In general, I think it's important to think about the typical conversion rate of prelaunch sign-ups to actual new users.

Here's what you might optimistically expect as far as conversion rates from your waitlist from Lenny's newsletter:

• For converting to a free sign-up, conversion rates range widely, from 25% to 85%, averaging around 50% if you get people off the waitlist in under a month and below 20% if you wait over three months.

• For converting to a paid account, conversion rates range from 5% to 25%, averaging around 20% if you get people off the waitlist in under a month and falling below 10% if you wait over three months.

• For converting waitlisted users to purchase a physical product, I only have a few data points in this bucket, but conversion rates are all below 5% once you roll your product out widely.

The conversion rate will depend on things like:

• How targeted your marketing was
• How long ago you collected sign-ups
• How good your launch is (are you optimized for conversions?)

I got 170 people, built MPV after that it was fiasco xD

I can't give you an exact number, it always depends on the scope of your application.

For example at out startup era.sh (a markdown note-taking tool for developers) we talked directly to developers around the world and actively validated it.

Is there really a number. Just market and reach as a many target audience as you can

They used to call this vaporware along time ago in the software industry.

Are you marketing it enough? what are the platforms you are using to market the product?

A lot of creators do this mistake where they don't market the properly and abandon the project when they don't see enough users. You need to put your idea out there for enough people to see and then see if there is interest among the users. If there is a 25%-35% conversion rate, that is a good validation of a product.