It sounds okay if you build a tool for twitter, instagram or any other big player with an open api for developers.
However, for the past few weeks, I'm trying come up with some weekend projects. Today I got a few more ideas.
Most of them circling around Substack. There were a post on IH where people talking about lack of customizability. First thing, it's possible to send form data to subscribe for a newsletter. It's not official so it's kind of a "use it at your own risk" thing. But it's easy, just need a place to deploy. Not easy to monetise except asking for donations. Then I thought I could design a few landing pages and include the form in it. But IDK since it's not an official tool, it might be a waste of time also beyond the limit of a weekend project.
While I was searching for that post, I found this one Distinguish - Custom domains and branding for Substack which offers custom domain, ability to change fonts and colors, well it's possible to create your own themes on Substack's non-public api. But again it's not public.
And the above solution is actually a feature presented to high volume users. e.g. notboring.email
So what do you think, would you take the risk or even ignore it because of the ethics?
edit: Custom url and page features are just my assumptions. I don't know if it's just for top newsletters or whoever asks for it.