For so many reasons!
I am casting a line to see if I get any nibbles.
Some players want to get right to the meat of the matter, so to speak. They will like One Shots.
Others will want to get a feel for my style, and will use the shorter roleplay to determine whether we are suited for each other, without investing a great deal of time before making a decision. These wordier and more detail oriented players will like One Shots as well.
I'm sure there are other reasons, but I'll let you ponder them at your leisure.
Uncle Helps Out. An RP wherein my niece is being left with me at my cabin on the lake, as her parents go on a long holiday. The girl has long been a favorite, and both of them look forward to having their own getaway. Make a Good Act of Contrition. I love the concept of a priest taking the confession of a girl in his private office. There may not be a lot of mystery in the play, but there is certain to be some excitement.
Dancer Makes a Move. The short story of a fellow at a strip club, whose friends treat him to a lap dance.
More than She Bargained for. A blind date starts off well, then the couple return to the girl's apartment, wher the guy determines that his date needs some discipline.