The N-Dubz singer won the ITV competition with her act Little Mix in her first year on the judging panel yesterday. It was also the first year in which a group managed to win.
She reportedly earned £450,000 for her stint this year, and will now allegedly earn "just shy of a million" if she agrees to sign on in 2012, according to The Sun.
A source said: "She's stuck by Louis [Walsh] and learnt a few tricks of the trade from him.
"Plus, she sticks to her views. Weaker people might have retracted what she said about Misha B hassling Little Mix to keep things upbeat but she didn't. The producers love her."
Little Mix are expected to earn up to £8 million following their win last night.
Contostavlos revealed that she plans on duetting with the girl group again in the future, after performing an Alicia Keys medley on Saturday.
> Simon Cowell backs X Factor result: 'Little Mix could be stars'