Audience Research.

I went onto Amazon and found the album Hey Ma by James which features the song 'Of Monsters and Heroes and Men' then by looking at 'Customers Who Bought This Item Also Bought' we can see that people who have bought this album have also bought other James albums and the lead singer Tim Booth's album. The fans of James seem to be only interested in music by James or the band members so there isn't a wide variety of interest in other albums or artists on Amazon when people by their music.

Here is a review of the album 'Hey Ma' by James: http://www.antimusic.com/reviews/08/James.shtml