Hi HN,
I'm Martin, and over the past 8 months, I've been working on a new product Tintage (https://tintage.com) where you can find niche places to advertise and their rates.
The problem it solves:
It's very easy to run programatic ads but there isn't really an easy way to find podcasts, newsletters, websites that do sponsorship/ad deals.
It also helps businesses that struggle to find advertisers.
So, it's essentially a dedicated site for any type of media that accepts advertisers and sponsors.
Feel free to add your site. Would really appreciate feedback.
Thanks,
Martin