340 waitlist signups, zero replies to my first email, is the signal fake Fake Door

Before anything else, split the 340 by where they came from. My guess is that one of the four places produced 250 of them and the other three produced 90, and that the 250 are people who browse launches for fun.

The source composition of a waitlist tells you more than the size. 40 signups from a trade forum where people described their actual problem in the comments is worth vastly more than 300 from a general audience, and if you had those numbers separated you would probably already know what to do.

An email address costs nothing to give away, so it measures curiosity rather than demand. Zero replies out of 340 is not a mystery, it is the measurement completing.

What you want is a request that costs them something small:

• 15 minutes on a call this week, with a specific slot offered
• a screenshot of the spreadsheet or whiteboard they use now
• $20 to hold a spot

Also check the mechanics, because they are usually wrong on a first send: is the from-address a person, does reply-to go to a human inbox, is the subject line something a human would write. "We're excited to have you on the waitlist!" from hello@ gets archived by reflex.

Rewrite it as three sentences that look like you typed them, and send to 40 people, not 340. You will learn more from 40 and you still have 300 left to try the next version on.

Put the ask on the confirmation page, not in an email. The three seconds after someone submits their address is the most engaged they will ever be, and "want to skip the queue? grab 15 minutes" with a calendar link converts far better there than in an inbox two days later.

41% open is fine for a week-old opt-in list. The reply rate is the tell, and reply rate is mostly a function of whether the email looks like it came from a person and whether the ask is small enough to answer in one line while walking.

"What are you using today?" is a good question but it is still an essay prompt to a busy tradesperson. "Are you doing this in a paper diary or software?" gets answered because it can be answered with one word.

340 emails is a list. It is not customers, it is not validation, it is a list. I had 1,100 and made $0, and the eventual first sale came from someone who was never on it.

Also worth checking your own spam placement - 41% open with 0 replies sometimes means the ones who would have replied never saw it. Send one to a Gmail, an Outlook and a hosted work domain and look at which tab it lands in.