Charli is the primary reason for the success. It's blatantly obvious lol. That's not to say Iggy doesn't play a role- some of her parts are catchy and the whole white female rapper gimmick helps.
Fancy is a jam, regardless. It's better than any Nicki song imo. Nicki is still the better rapper, obviously. Her features slaughter anything Iggy has done thus far.
Problem is TERRIBLE. Ariana in general is a total BUST.
And yeah Starships > SuperBass
SB is boring and goes nowhere, at least Starships is unapologetic in all its sellout glory
Seriously though, I like Nicki. But, the music she has been putting out has been horrible, Pills and Potions is cute. But, she can come so much harder than that.
I like Nicki as well but i've never been a fan of her music besides (superbass because it was shoved down my throughout by pop culture). Her music simply isn't all that.
Her features are 10x better than her solo efforts.
I think "Work" and "Change Your Life" could easily be Top 5 hits, too. And both those songs would prove Iggy doesn't need a pop girl to sing the hook. She really is more comparable to Missy Elliot than Nicki.
Problem is TERRIBLE. Ariana in general is a total BUST.
And yeah Starships > SuperBass
SB is boring and goes nowhere, at least Starships is unapologetic in all its sellout glory
Yes, Lonny laying pipe internationally. I have heard stories about how he does some of these white boys when he goes out on tour. 
