Mills, who was voted off in the ITV show's semi-finals, was compared to the young Joe Cocker by judge Simon Cowell.
The 26-year-old is currently recording his debut, which will feature songs from X Factor and his own material.
Why?
They sign a six-month contract with the show, which includes the tour. It means they can't turn around and say 'sorry, I can't do the tour/X-Factor Reunion special, I've got gigs booked/I'm in the studio' etc. Given Ben and Ray have supposedly already signed deals, maybe they've changed the rules this year.