An event, photo, rumor, or other happening that is worthy of posting on your Facebook profile for everyone to see.
"I just partied, drank scotch & sang karaoke all night with guys and their Korean servant girl harem in their mob lair without paying a single yen. It was definitely a Facebookworthy evening."
Not of business. Used in writing to inform readers that the content to follow is not work-related.
Subject: NOB: Party at my place
Hey, don't forget the tropical oils. Party at my place.