BTW flopped because it didn't match the zeitgeist of pop culture. I dunno how she fell off so quickly with what was happening in the world. It was risky though, honestly. There's some instrumentals and concepts on there a pop girl in 2011 would never have gone for.
ARTPOP is her safest album.

It bombed because unlike Katy's safeness, there was no charm if you weren't a face-painted lilMonster.
The Fame was definitely art school-y, but that's what made it popular. It came about during a weird era of cheap reality television & TMZ controversies, feeding into the whole "i just lovee $ & sex, giggles" trend in a cool retro throwback sense. Everything was right about it.