Why are digi-packs so important?

Reminding myself of the importance of digi-packs ..

                  

this digipak for Katy Perry's 'Teenage Dream is a classic example of why digipaks are important

The digipak contains...

• A number of photographs of the artist
• A theme (candy) - it is also candy scented
• A bonus CD

These features cooperate to make the album 'special' enough to buy, they set it apart from a normal CD 

and give fans good reason to invest money in the product.