Launch day: turning a waitlist into installs that land in the right onboarding

A waitlist is a list of people who said they were interested once. Launch day is a single email to all of them, and then a store listing. What you learn from the default version of this is how many installed. What you don't learn is which of the pre-launch channels — the product-hunt post, the founder's thread, the newsletter mention — produced the people who actually stuck.

What problem does this solve?

Each waitlist signup came from somewhere. If the launch link remembers where, the install attributes back to the channel that produced the signup months earlier, and onboarding can reflect what they signed up for. That turns launch day from one number into a ranked list of the channels worth repeating.

How do you set the links up?

Store the acquisition source against each waitlist entry at signup. At launch, each person's link carries that source and, if they told you anything about their interest, that too. One template, personalised per recipient by your email tool.

{
  "deepLinkPath": "/onboarding",
  "customData": {"src": "{{signup_source}}", "wl": "true", "interest": "{{interest}}"}
}

What about the people who install from the store listing directly?

They'll show up as organic, and that's correct — they are. The waitlist link is what separates 'organic because of launch buzz' from 'came back because we emailed them'. If the two numbers are similar, the waitlist did little. If the waitlist dominates, the pre-launch work is where growth came from.

• Send the launch email in waves if you can. It makes the server load survivable, and it lets you compare open-to-install by wave.
• The store listing will get traffic you can't attribute. Don't try to; use the waitlist cohort as the controlled comparison.
• Keep the waitlist link live for weeks. Launch-day installs are the minority; the long tail from people who saw the email late is often bigger.

What should the first screen show a waitlist user?

That you remember them. The payload says this person signed up months ago and told you what they were interested in; the first screen should say so back — skip the 'what is this app' introduction they already read, lead with the thing they said they wanted, and if there was a promise made to early signups, honour it here without being asked. A waitlist user who gets the same onboarding as a store-organic install has just been told the wait meant nothing. The point of carrying the source and the interest across the install is to make the opposite true.

Which metric should you watch?

Day-7 retention by signup source. Installs by source tells you which channel was loud. Retention by source tells you which channel found people who wanted the product — and that is the only list worth spending on next time.