Although 'Day and Age' has sold 2.5 million copies worldwide the 'Mr Brightside' rocker wasn't entirely happy with the sales figures, especially when compared to the 7 million their debut 'Hot Fuss' achieved.
He said: "How much does it bother me? I think about it every day. I've thought about it today. I've already talked about it today with my press officer."
The group's second album, 'Sam's Town', achieved worldwide sales of 4.6 million and also won a BRIT Award for Best International Album.
Brandon also admits the band's songs can sound "contrived" and too "perfect".
He said: "If you look at us and you hear it, it's almost too good to be true. We have good songs, it sounds perfect, it sounds contrived, but it wasn't."