On HN months ago, I made a list [1] on publishing small databases, and I remember that I could not find a good service under "List sharing" (maybe one). Yours fills that slot perfectly.
I have some suggestions: For initiating the DB, offering import (csv/sheets...) would help creators jump in. Then, for collaboration, you could offer the option to add without any account at all (just send the "under review" form to the moderators), or maybe also add more signup alternatives.
As for monetization, I suggest in the future you limit only "private" DBs (= me and other moderators) , so people can still create unlimited public ones (good for spreading the word).
Good luck!
[1] https://news.ycombinator.com/item?id=34561292