MY USER demographic includes my self-registered age of my dear deceased dad. So I'm pushing the average age of YouTube users closer to the 30 year old mark. Here's a summary of YouTube usage from Mashable Labs:
Across the video-sharing space, people gravitate toward short clips, 2-5 minutes, and they are grazing when they find their clips. I see this now. Co-workers click into YouTube when they have a couple of extra minutes and students graze arond between academic classes. I never see people sitting on the edge of their seats watching watching full-length movies. I wouldn't sit to watch 50 minutes of Bladerunner clips, even though I really want that movie clip.