I think main pop girls are girls who have generally made a huge impact on pop music.
If y'all are gonna base your decisions on the previous album's sales, like for Ariana outselling Anti, then obviously the list is going to keep changing. Ya'll dont get it.
I love Ariana, and she's becoming very successful in recent years, but she's nowhere near a MAIN pop girl, neither has she changed anything.
I would agree Rihanna and obviously Gaga deserves a spot in the top 5.
I wouldn't say Taylor deserves to be there considering she's only had ONE pop album, albeit a very successful one.
OT: Beyonce, Adele, Katy, Rihanna and Gaga.
Obviously girls like Madonna and Britney deserve a spot but they're past their prime. They were once main pop girls tho.
Rihanna AND Gaga. If one has to be picked, then it's Rihanna. Katy is on the same level (commercially NEVER in terms of talent) as Gaga though, we'll see in their next eras...