The Teenage Dream era is still going for a reason, I guess.
Anyway, TD established Katy as a US Chart Queen, while TFM set Gaga apart as a global icon. Both eras were successful in their own right.
Still, it's pretty sad that Bad Romance, the biggest single from TFM era, was eclipsed in every possible way by Tik Tok, a debut single by a debut artist. In the US at least. TD singles were indomitable.
