Netflix may be the undisputed king of streaming, but it's facing a new challenge: "the sophomore slump." Internal data reported by Bloomberg show audiences dropping off dramatically for follow-up seasons of successful shows.Series including "The Night Agent," "Beef" and "Avatar: The Last Airbender" lost 50% or more of their original viewers when they returned for season two. To figure out what might be going on and how Netflix could respond we called up Brandon Katz, director of insights and content strategy at Greenlight Analytics.More on this“Netflix Viewers Are Abandoning Shows After One Season” from Bloomberg“Of course viewers are giving up on Netflix shows” from The Verge