Great video, thanks lex. When you guys were talking about clips i thought about pornhub's videos where they have markers indicating the start or transitions of different sexual acts. For a second I was amazed that pornhub was ahead of google on this one,  but then I realized they probably use a 'heat map' based on where people skip the video to, which wouldn't work as well for youtube as the important content isn't always evident by simply sliding through the thumbnail previews of different timestamps. Definitely a much harder problem for a product like youtube to solve