I actually came here to say this, but it's more of one of the reasons than the reason.
Anyway, I prefer her to Cheryl Cole and she actually brings something to the table. Not anything fresh or exciting just something. But, she is sorta bland and lacks a standout personality outside of her colorful clothing. Also, her childish vocal tone could be a turnoff to listen to for some people.
I think she could be commercially successful if she wanted to be, but she's clearly stated that it's not a priority. She's just doing her own thing. She's styling herself as an indie artist and she already is building up a cult underground following. I think she's doing quite well for herself to be honest.
I think her & Pixie are the most promising artist of the new UK Pop Girls. Hopefully she blows up along with Pixie. Who knows maybe she could be the next big local thing like Katy Perry is for the US.
She's not a good singer, she's got no personality, about as much charisma as disintegrating toilet paper. I don't understand how she's so popular on ATRL.