Need help with growing the waitlist

I am working on an AI - enabled platform that helps optimize household spending by working as an intellgence layer to make informed purchasing decisions. I started working on this after interviewing 100 households.

Within first week of launch I was able to get 400+ signups through facebook and organic outreach, but now I want to increase the outreach strategy. For the operators

1. what would you do to spread the word out?
2. What king of content should be created and how can we promote it?
3. Anything else I am missing on?