However I was not really able to monetize in any form (needs permission from Spotify, and Stripe shut down the account before it got to even do anything). Did you encounter similar issues and if so how did you circumvent them?

I'm at a loss now and on the verge of shutting it down, but I have a few hundred users that periodically email me to ask for fixes / new features, and it pains my heart to just give it up like that, but it's just not making any sense economically for me now.

Charge $1 / user and setup targeting at genre level for MVP and similar artist level at your later stage version.

So a label/artist says "we want people who like electronic", you have 150 people in the list. You charge the label/artist $150 to add their song to the playlists which you generate.

In my case it's been a better-to-ask-for-forgiveness-than-permission situation. I've had almost no official contact with Google and do my best to abide by their terms.

Feel free to reach out via email if you'd like to chat! There's a chance I'd be interested in buying it if you're planning to shut down.

I believe Spotify has some API terms that say that explicit permission must be granted for monetization. I initially also went for the 'ask-for-forgiveness' route but Stripe didn't allow my account to get started at all as it was considered high risk.

For now I'm going to fix some issues and try to do more reaching out / marketing, and then I'll try reaching out to Stripe again - hopefully this doesn't look that shady / high risk anymore.