Katy Perry consistently gets radio and digital hits. Is this because her music has the most mass appeal of the other pop girls? Unlike Beyonce or Gaga, Katy's music isn't always about sex or being under men. Is this why she is more consistent than other pop girls, with the exception of urban rock icon Rihanna.
No, she's an indie queen. Two more Grammy nominations and she'll be tied with Björk as one of the most-nominated-without-winning artists of all time, so surely she's not commercial?
She plays it safe. It works for commercial success, albeit it's total boring - which is why she doesn't have as much acclaim or credibility as the others do.
Her music is easily digestible, especially within the younger community, and the little kids. My two nieces love Roar, and sing along with it everytime it goes on the radio.