Uhm Miley released her single not even a month ago yet and has already out peaked her on Billboard and has been #2 for a week on iTunes. Selena is still in the Top 10 on iTunes and both her and Demi have sold ~1.5 million while Ariana has sold 1.2.. She may outsell Demi, but I dont see her outselling Selena until her song just freefalls out of the Top 100. And when Ariana is still here years to come and still getting hits and they aren't then say that until then the only people she is slaying are the other Nick girls who have failed to get hits