Definitions and purposes of: A digipak for the band/artist

A digipak can be described as a deluxe edition of a released music CD often featuring exclusive tracks, a larger information booklet sometimes including behind the scenes information and song lyrics. 

They are often bought by a more dedicated follower of the digipak's producer so are aimed at appealing to the core following. 

The are a more recent product spurred on by the popularity of the gaming industries often multiple editions of a video game e.g. limited edition and collectors edition. 

Digipaks are  more expensive than a conventional CD due to the exclusive content. The usual CD costs around £9 while a typical digipak would cost around £12-£15.