My approach with Code Hike (https://codehike.org/) was to add a sponsor-wall to some parts of the docs, not sure if it falls under any of those categories. It's working decently well ($600 per month).
> The code of this demo is hidden until it reaches five sponsors.
> Become a sponsor for $9 a month to have full acces to all demos:
Maybe I misunderstand, but I could either pay $9/month and would be able to access it directly, or I wait until you get 5 more sponsors (for that specific page) and then I'll be able to access the content for free, like everyone else?
So if I end up sponsoring the page to view it, I could end up being the fifth sponsor, unlocking the page for everyone and ultimately spent the money for content that now everyone can view too?
And making a subscription makes the value prop even more confusing.
Seems like an own-goal.