Why genies are common in arabic literature?

Firstly, genies (or Djin, as they are more properly called) aren't that prolific in Arab folklore. Arabs, unlike the Norse, Greeks, or Celts, have no collection of mythical monsters. While Greek mythology has a plethera of dryads and similiar creatures and the Norse have dwarves, giants, and dragons, the Arabs only have Ghouls and Djin (and Rocs). Due to the limited selection of mythical beings for protagonists in Arabic litereture to encounter, Djin repeatedly appear.