Libraries could, and do, use this medium to entertain and advertise, as evidenced by those looked at in this exercise, which included a teen rap, a library week promotion, etc. To reach an audience of the unconverted the titles need to be intriguing. I couldn't look at any of the Infotubey-award winning library videos - it froze everything.
The YouTube site has been easy to use, but I haven't stretched its search capabilities too much.
The video I've chosen is no longer on YouTube, but on Brightcove. This is of El Camino del Rey a walkway which was built in 1901. Mountaineers use it for access to Makinodromo, a sector of El Chorro. I seem to have managed to embed the video but it might be quicker to look at it by going to the link http://www.brightcove.tv/title.jsp?title=1438490562