bonus tracks 

since a cd has a larger capacity than a vinyl record some record companies feel compelled to fill in that extra space when a classic album is re-released on cd

Bonus tracks are often alternative versions of songs already on the album or in some cases they are songs that weren't on the original release simply because they suck. Some people think bonus tracks ruin the integrity of the original recording.

bonus tracks by Mr.Juan-derful April 18, 2010

Japanese bonus track 

If you visit band or lyrics websites, you may often see extra tracks in discographies described as being 'Japanese bonus tracks'. This is in part due to CD prices in Japan. To stop shops from buying cheap from abroad, the Japanese version may include an extra song.

Lost Prophets, OutKast, Sonata Arctica, Pain of Salvation, Less Than Jake to name some of the artists with Japanese bonus tracks that come up first in a Google search.

Japanese bonus track by Mark_H September 5, 2008

Japanese bonus track 

If you're someone like me (one who feels incomplete without having every album/EP/song from a band) these can get EXTREMELY annoying. For some reason which I don't know (I was told by a friend that it was some sort of agreement Japan had with the music industry) they always get them.

Person A: YES!! I finally have every song by DragonForce!
Person B: I think you forgot about those Japanese bonus tracks that appear on all their albums.
Person A: What?
Person B: You don't have 'Where Dragons Rule', 'Cry of the Brave' and 'E.P.M.'.
*Person B walks away*
Person A: My life is over *sniff*
*Person A pulls out a gun*

Japanese bonus track by gets annoyed when this happens March 7, 2009