The big bumps were mostly due to massive AC updates I think. Applause wasn't that big on that format (and no one ever claimed it was), it was mainly a Pop/HAC hit (in fact, it is currently higher than LaRoar on Pop). The song is still top20 into 2014 when it loooked like it wouldn't even make it four months ago.
Anyway, it isn't her biggest radio hit and people who say that deserve a bit of LaDragging.
