Tool To Find Newsletters To Sponsor
This is an utterly shameless plug, but I'm working on a platform called AdCove.io that helps advertisers find newsletters they can sponsor, in their niche, at various audience sizes and price points.
I'm launching on ProductHunt next week (currently set for February 8th) and would love to get more users (on the advertiser's side) on the platform before then. Normal pricing is $200 per year for access, I can discount it down to $40 for your first year which will be the ProductHunt promotion, but if you're willing to offer me feedback (keeping in mind the drawbacks of no-code) I'll happily give you the first year free.
Fair warning, there is only 1 newsletter listed right now, working on converting the other 20ish off of the waitlist (getting very difficult). But working on picking this up to make it worth while.
Also if you want to be notified of the ProductHunt launch you can do that here: https://www.producthunt.com/products/adcove
In my opinion, you should't charge anything until you have a solid number of newsletters included.