Almost everyone who is anyone knows about the massive video catalog of YouTube. You can find almost anything there.
But YouTube represents the Shallow Web. Almost a 99.9% / 0.1% rule. Lots of low authority junk (99.9%) with a little bit of high quality stuff (0.1%).
Alto, YouTube is really good at hitting the SEO and getting first place in google. Therefore shallow web.
But what is a video site with high authority – university, military, and government lectures is videolectures.net. This site doesn’t do a very good job on their SEO and therefore it doesn’t show up in the first few pages of most search engines. As we all know, when your site is pushed way back in the list of returns, you become a kind-of-deep-web site. But this site is phenomenal for its content and should be known by serious researchers.
An excellent example is a lecture on OSInt (open source intelligence) by a European Commission staff member
Open Source Intelligence