If we go by that logic, Katy can't even compare to Gaga, as her discography has yet to outsell Gaga's debut album
The Fame sold 5 million copies in its first year. It was then re-released with an entire new studio album attached to it, and the combined albums wound up selling an extra 10m copies. There's no apples to apples comparison between Gaga's debut and any other album
2 albums outselling 3 (allegedly since Fad's recurrent sales have been the pits for 3 years now) doesn't sound as impressive as "her whole discography got outsold by a debut album" so I understand.
Speaking of Ginger, X, released six years later after further tragic declines in sales, will end up outselling what The Fame would have done without that re-release. And his tour is playing to much bigger venues than the Monster Ball.
Gaga her peak is so overrated by her stans. Even Ginger is outdoing her.
And his tour is playing to much bigger venues than the Monster Ball.