Michael
I Love YTtalk
Well PMing unless the channel lists an email is really the only way to contact channels
Every network does it, even the "big rep" ones like Fullscreen
I've only heard of larger networks doing it to rather large channels myself, I am pretty sure Fullscreen and most of the others don't have recruiters who send out invitations to the vast majority of channels out there. Spam is spam pming or emailing, the messages weren't asked for or opted into.

That's alot of PMs lol