YouTube Video Annotations allowed video creators to add interactive commentary to their videos containing background information, branching ("choose your own adventure" style) stories, or links to any YouTube video, channel, or search results page. Launched June 4, 2008; shut down January 15, 2019 — it lived 10 years. One of 37 Google products killed in 2019. https://www.theverge.com/2018/11/27/18114581/youtube-annotations-discontinued-january-2019 Data: Killed by Google (killedbygoogle.com, MIT).