via MTV:"After a lackluster turn on the show in which Britney Spears failed to goose ratings for Simon Cowell's reality singing competition The X Factor, sources close to the production confirmed to MTV News on Thursday (January 10) that the singer has quit the show because she knew she would not be asked to return for this fall’s third season. Spears will be a one-termer after ratings for the show’s second season suffered a double-digit dip last year”