Also, the sages of Youtube include mini-shows, from 1 to 3 minutes, and a couple of the techniques they use:

"watch for the surprise ending."

And a really clever one. They'll post an obvious error in the description, sometimes with a garish still photo that may or may not actually be in the video. But self-important viewers will be all over it: "That's a spotted leopard, NOT a hyena!" sort of stuff.