Catagory systems:

• Styles : vlog, creative production (shorts, animations, mashups), clips (shows), advertising (trailers, commercials)
• Intent : communication, file sharing, discussion, marketing, critique, rememberance/memorium, idea distribution
• Function : critique, comment, discussion, identity expression, creative expression,
• User generated vs Pro generated - music videos vs covers/mashups

Labels used in YouTube:
Autos and Vehicles : racing, stunts, crashs, new models, tricked out cars
Comedy: spoofs, original content
Education: discussion, serious thought, innovation, critique, lectures, speakers, campaigns
Entertainment: celebrities, tv clips, trailers, commercials, music perfomances, music videos, bloopers
Film and Animation: anime, trailers, movie clips, mashups, independent series (e.g. Grickle)
Music: further divided into genres
How to and Style: tutorials, explanations, product demonstrations
News and Politics: speeches, camgaigns, statements, critiques
People and Blogs: vlogging, sexuality
Pets and Animals: in the wild, in the home, and interacting with something amusing or humans
Science and Technology: new gagets
Sports: clips, replays
Travel and Events: weather, roads, 'exotic' places and events

Community - contests
Channels - the uploaders