I guess, if its a thread like the one where everyone first saw Gus' edit (a bad day for you evan, i know) then its cool, cos its bringing something to everyones attention and its often something that can spark a lengthy discussion like that video did or could stoke out tons of kids who may have missed say the new Clown School or 4bi9 edit somewhere else.
If its just like hey look! I made a video, this is shameless self promotion and it'll get more views here so i'm posting it up! then thats pretty wack and shouldn't be aloud.