We're only talking about the current pop stars, since it has been proven that established artists like Britney Spears and Beyoncé all have loyal fanbases that help supporting their longevity in the industry. Out of these new pop girls of this generation, who have the most loyal fanbase that will support them even when they're out of the spotlight?
It depends on the person. People are "loyal" to genuine people, genuine celebrities. Britney Spears is genuine,
so her fanbase will always be there. Ke$ha and Rihanna are genuine, so their fanbase will most likely stay.
People who are disingenuous and change themselves for whatever reason, will have a fickle fanbase.
We are so perfect. 
