Why did 'Perfume' flop?

[Calm Before the Storm]

The song is just not great overall.... The vocals are too different-sounding coming from Britney, the production is quite boring, and altogether it was just pretty bad (including the whole boring video...)
Also, I think it wasn't a good time for her to release a ballad. Ballads can be successful if they're released by an artist that is really popular at the same time, and Britney was not at her best at the time. Right now, on the other hand, with Glory..... 

[Million Billion]

It is a great song and I loved it since the 1st listen, the lyrics are very girly, well, it's Britney, she said it was a personal album and that's what we got a personal ballad and I loved it, it's very relatable  (sorry that year I broke up with my bf)

but yeah, the video was quite boring and monotonous and she never promoted it, aside from gays and britney fans, the GP barerly knew it even existed, plus she let the BJ era die as fast as the Vegas show started. 

[Rachel Green]

Honestly it deserved to do better. Her vocals sounds very good and it's a nice song. If it had been more succesful Alien would've been a single 

Its music video doesn't even have 30M views #Justice4Perfume