I don't think she would retire, she would simply try even harder for a hit next time or just think "forget it" and make something totally personal / not trying to be commercial.
exactly, I'm seeing rnb making a big return late this year into next year so if it doesn't do well I see her going back to singing real songs, not more NMT or Your Body stuff. The people with the most success and/or acclaim this year have been people making the music THEY want not the ones making what's hot.
If she flops, I will personally still be interested in her material because the amount of commercial success an album has does not effect MY opinion of music. I like some of Xtina's music and I love Your Body so I'm excited for what comes.
Maybe her Pop career will. RCA definitely will stop investing in her music projects. Despite fans' beliefs that RCA has an unlimited amount of money to throw at promotion, they don't, and they will stop whenever they believe the return on their investment isn't worthwhile.
She'll never be "done" per say, but her career as a prominent pop star will pretty much be dead.
She can always make a comeback, but the more "flop" albums you add to your discography the harder it becomes. If Lotus flops, she will either pull a Mariah (Emancipation Of Mimi), or pull a Janet (Damita Jo, 20 Y.O., Discipline, aka a continuous stream of flops).