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.