Promote on Youtube

can anyone tell me, what do you promote on youtube?
and how much do you gain?
i need a little of research for youtube.
so please help me guys...

Thanks

videos

anything can be promoted on youtube. Clickbank, CPA, free movies with gateway, ringtones, pay per isntall, porn...and the list goes on

it really depends what the movie is about and what title and description it got.

but then again i think you can take pretty much any movie and promote anything, if you at least got a domain in the video with some instructions, good title, and a link and "everything else" in the description

how about comment spam?
what the best thing that should i promote if i use that method?

anything that relates to the video