In terms of recorded music, a bonus track (also known as a bonus cut or bonus) is a piece of music which has been included on specific releases or reissues of an album. This is most often done as a promotional device, either as an incentive to customers to purchase albums they might otherwise not, or to repurchase albums they already own. In contrast to hidden tracks, bonus tracks are included on track listings and usually do not have a gap of silence between other album tracks.
Many international releases — most commonly Japanese releases of foreign artist albums, but not confined to just Japan, or just music going from West to East — contain a few bonus tracks. These are often B-sides from singles. Alternative takes are other tracks often released as bonus tracks. It has also been said that this is the industry's way to get consumers to purchase albums from Japanese distributors, instead of the often less expensive imports from the West.
It is not uncommon to release singles as bonus tracks on re-issues of old albums, where those weren't originally included.
With the advent of online music stores, such as Apple's iTunes Music Store, à la carte song buying has become the norm. Bonus tracks are often included if a customer buys a whole album rather than just one or two hit songs from the artist. The song is not necessarily free nor is it available as a stand alone download, adding also to the incentive to buy the complete album.
Japan is one of the largest music markets in the world. However, domestic pressings are more expensive there than in the U.S. or Europe, so Japanese labels often arrange for additional content in the locally manufactured products as a marketing technique in an attempt to be competitive with imports.