His videos on YouTube when he teaches people how to do board-level Macbook repairs, for free (while advertising his own business of course): https://www.youtube.com/user/rossmanngroup/videos

Even though I'm a programmer and not really a hardware guy, I find watching him repairing stuff very interesting and oddly satisfying. He often even does all this on a live stream.

PS. For some reason most of his videos get a "do you want a website" preroll ad, which is already a running joke on his streams.