[makeee]

Found early adopters for https://divjoy.com by tweeting out some screenshots of the private beta to my ~1k or so followers at the time and asking if anyone wanted early access. Also started writing some short blog posts about React.js (related to my product) and tweeted those out as well + cross-promoted from the blog to my product.

You're going to need to get 1000+ people to hit your site to get 100 beta users so just try to get some exposure in any relevant community you can. Asking for advice is a great way to share your product without coming off as too spammy, so I'd update your post with a link to your product ASAP!