I got both of these in my email:
I thought, gee, I wonder if I can find them on YouTube. Well yeah, they were there and easy to find too, at the top of each search.
I have only seen them for the fist time recently, but it seems that they have been popular on YouTube for a while now. But the ones I got in my email don't have the advertisements on the edges. When did Youtube start doing that? I don't like the ads overlapping the video, they are annoying and detract from the experience. I say put the ads below the video, not OVER it.