To be honest, we all kind of share in the blame for her album not doing so well. Carousel has been a single for over two months now - how many of us took the time to call our local radio stations several times a week and request it? How many of us linked to the youtube video on Facebook, Twitter, Google+, etc, etc? How many of us played the song for our friends and family on more than one occasion? I mean, it's easy to sit on a forum and talk about how much we love her, but we need to walk the walk if we want the next single (if there is a next single?) to do well.
Of course, I'm sure most of you have done at least some of those things, as I have, but Lady Gaga (to name one good example) didn't get to be famous by divine intervention: her fans worked their ASSES off to get her music heard back in 2008. I don't know if any of you know a singer called Utada (she's gigantic in Japan, relatively tiny in the US), but when her English album came out, someone organized radio station call-ins to get them to play her music. Her single never made it to the Top 40, but it did get into the Top 50. The point being, to a certain extent it's kind of the fanbase's responsibility to get the music played, just as much as it is the artist's - and fans can only do so much, but we can do something.
Sorry for the random rant, I'm not actually angry/upset or anything, just giving my two cents on the matter since I know a lot of people are kinda bummed about her sales.