Will.i.am has a theory about why The X Factor delivers bigger stars than The Voice
The Voice judge Will.i.am is no fool, he knows why rival show The X Factor produces so many hit artists.
The series has churned out a string of success stories, including superstars One Direction, Little Mix and Leona Lewis.
Now Will has said that the reason The X Factor is a hit machine while The Voice is not is all down to the man pulling the strings - Simon Cowell.
He told Q magazine: "OK, I can say it now - before I couldn't, and now I can. The singing shows that have been successful are 'The X Factor ' and 'Pop Idol'. Who's the consistent person working on those shows? Simon Cowell.
"Here's a person that ran a record label that is attached to TV shows - of course someone is going to turn into a f***ing star.
"The problem with The Voice is, the people that are on the chairs are not plugged into the record label. Our show is about celebrating awesome voices. He's looking for 'The X Factor '. We're trying to get citrus out of apples."
Will has recently admitted he does not know if he will be returning to The Voice when it moves over to ITV from the BBC.