Advantages: You can find practically anything
Disadvantages: Low quality
I love you tube, though not specifically for the visual treats it has to offer, more for the music side of it.
If I fancy listening to something, I just key the title of the sone and the performer into the approprite field on you tube. Nine times out of ten someone has uploaded a video of the song in question. Though I tend to open up anothe fire fox or google window and get on with whatever work I am doing at the time, while I have the happy tones of my chosen music humming away from my speakers.
But yes there are times when I fomd te visual aspect of you tube very useful.
Back in the good old days, when we only had the BBc and ITV, there was a good chance I would get to see the football highlights, without some subscription to somewhere or another. well with you tube, chances are some one has uploaded the highlights. Yay for you tube.
Summary: feast for the eyes and ears