I love this. And I would like to say that I think many of the highest-voted comments have it wrong: I WANT TO PAY for using the app in exchange for good privacy/ethical practices of the app/company making it. I don't even comment here on HN much but I was moved to speak out about your post. (And its the right day to post this, given the protest of so many subreddtits due to their API pricing and terms)
That said, yes you may still get a "network effect" from not enough people registering/using the app. But hey, I applaud the attempt and hopefully it will get some users/traction.
Last question I would have is: how does it compare/contrast/integrate with other, possibly federated, social services such as Mastodon?