She was going through a public meltdown at the time and a HUGE media backlash that she sometimes played into, it was literally bought by her loyal fan base because the GP had turned. So it did quite well when you take that into consideration. Not to mention it is her most praised album and is acclaimed as well not to mention it had a top 3 hit which has the iconic "Its Britney Bitch". So i personally don't see how it flopped
It's as if you're trying to remove the heavy context it had
She was going through a by the media created breakdown
She had a fail VMA performance
And then she had a comeback with Circus