Forgotten landing page shockingly attracting emails...

Hi there,

First time caller, long time listener here.

Back in September, I created a quick landing page for an indie idea I had. See here:
https://mypicturance.com/

I spent a week or two running some FB ads to it (several hundred dollars), hoping to get some people to put in their email, as a way to validate the idea and determine if there's a scalable CPA. A grand total of 1 person put their email in. So I promptly forgot about it and moved on.

But I came across it in Github yesterday and checked the netlify form, and about ~30 people have put in emails since then. Netlify is supposed to filter out spam emails. I've emailed a few of the emails to see how they found the site (I didn't have Google Analytics on it because I'm dumb)... haven't heard back yet. I literally didn't post it anywhere.

Question is.... are emails an indication of real interest? Should I spend some more energy on this and see if there's something there? Maybe actually build the thing and see if I get some paying customers?

Thanks!