A slang term for the universe that YouTube spawned, it specifically refers to dozens of video websites. Check it out...
Historical perspective: According to Steven Leckart of Wired
in June 2009, as of the third anniversary of the YouTube explosion, and
since the site's epic takeover of all things video, a server-farm-load
of specialized copycats has swiped its sobriquet. Got time to waste? Go
tubing. WARNING: Some of these sites are not appropriate for children 12 and under.
Listed in order from safe to NSFW, here's a sample of what's out there: