JonTron and a number of other video content creators on YouTube are sponsored/brought to you by Audible or Audiobooks or some other name I can't actually rememb

JonTron and a number of other video content creators on YouTube are sponsored/brought to you by Audible or Audiobooks or some other name I can't actually remember because by the time they do that bit I've already closed the video (thankfully most of the creators do it at the end of their videos, not the start of them). So I'm not sure that they do - maybe they prohibit turning on ads and "double dipping" the videos? But I've ran an adblocker for years so couldn't tell you if the "brought to you by ____" videos have ads or not.