Well right now it's used more for social board, but most of my 'friends' on it are people that hang out at the club I play anyway. So when I make announcements, I do use the board there so everyone will see it.
I know others utilize it more for things like you said with the video clips & Pics & I may go there as well. Just another way to advertise like any good business should do!
I work the search engines - although I have fell off a bit due to lack of time, used to be in the top 10 on most for tacoma karaoke. Have my websites which gets used alot, had new people in this weekend had all their slips already pre-printed from my site. Also utilize any karaoke forum that has a 'where to sing' for those looking.