I would have posted this in the other thread, had it not been closed.
Not to be a downer or anything. The main reason Gaga has been doing as well as she has is because of the marketing dollars that her touring company (LiveNation) is putting forth. Her manager, Troy Carter, said it himself.
If Rihanna was touring through LiveNation, she would probably be pulling similar numbers throughout the globe as well.
Except maybe Asia, because Gaga has been able to crack that market in ways that not many artists other than Avril Lavigne have been able to do.
Basically, I'd say it's a combination of star power and marketing. They go hand in hand. Yes, Gaga is a
huge star in her own right, but it's not really fair to ignore the importance of the promoters.