There's http://www.adweek.com/socialtimes/youtube-ads-highest-conversion-rates/204145, and https://www.thinkwithgoogle.com/articles/driving-donations-digitally.html
What’s more, they take action quickly, as 39% of donors reported that they look up an organization within 24 hours of seeing a video ad.
That last one is from the owner of Youtube, so take whatever grains of salt you think are appropriate.
Has anyone tried advertising existential risk?
Bostroms "End of Humanity" talk for instance.
It costs about 0.2 $ per view for a video ad on YouTube, so if 0.2% of viewers give an average of 100 $ it would break even. Hopefully people would give more than that.
You can target ads to groups likely to give much by the way, like the highly educated.
I posted this suggestion in the open thread as well, before I had the karma to make a thread. That okay?