A study published by Princeton University has found that only 10.5 percent of the YouTube videos containing affiliate links assessed in their sample group adequately disclosed the nature of those links. The FTC requires the disclosure of any sponsorship or relationships with brands or retailers, but the regulations are more open regarding affiliate links where no direct sponsorship exists. The researchers are hoping to develop a browser extension that detects common affiliate programs and notifies the user of its presence.
https://www.notebookcheck.net/Study-finds-only-one-tenth-of-YouTube-videos-with-affiliate-links-properly-disclose-them-in-the-video-description.293204.0.html