Demi "Slaying" by a mere 20,000 copies?
These Demi vs. Selena arguments are SOOOO stale at this point.
They (and Ariana) are just placeholders for the main pop girls who will hopefully return to the music scene and liven it up a bit in 2016. They are ALWAYS going to be second tier B listers and are literally on the same level. The stans need to accept it. Selena is slightly bigger in the US and Demi is slightly bigger Worldwide. Aside from a few differences, they're on the same exact level.