Got 1,000 signups on launch day. 950 Of them never came back.

We got a traffic spike last month and had over 1,000 people create an account in 24 hours. I thought we were set and actually started celebrating.

Checked the DB this morning. Literally 12 people are using the app regularly. The rest logged in once clicked around for 30 seconds and vanished forever.

Is this normal bounce rate, for launch traffic or is my onboarding flow completely broken? How do you actually retain people who sign up out of curiosity?