I only joined facebook about a year ago.
I love it! I couldn't give a sh!t about getting "found out" since I'm not looking for a relationship anyway. I've posted on there about chicks I've banged, random encounters (always not going into explicit details, never any names) and chicks dig it!
Last year, I got a chick with a boyfriend back to my place by chatting with her on facebook (although I had seen her in person and been flirting with her earlier in the night), narrowly missed out on a threesome with her and her friend, but banged her.
Earlier this year, I've banged two chicks who randomly added me on facebook
I've added a fair few random hotties (friend count all up is about 365), amazing how often they accept (only target those with some mutual friends). Most I don't chat to though, just add them as social proof.
Last year when I was banging a 29 year old for a few months, she actually thought I was cheating on her with an 18yo since some pics of me and her appeared on facebook, ironically I never did...ha ha
It is important to follow the rule of never posting a boring profile status update.
My status updates are always entertaining, and mainly revolve around going out to party, drinking, chicks or an ambiguous combination of all 3 (leave a bit to the imagination, to let them wonder and stoke jealousy in any female readers). Shallow maybe, but I find it entertaining.
I use facebook to keep in touch with friends or family not living nearby, can't imagine what I ever did without it.
My only rule would be to never add a chick after you have banged her unless she adds you first. And even then, do it with caution.