The document discusses why the iPod is successful. It attributes its success to two main reasons: 1) its innovative product design and 2) the iTunes music store. iTunes disrupted the traditional music industry model by allowing people to purchase individual songs for $0.99 each, which helped drive iPod sales and gave Apple 80% of the online music market. While iTunes profits were low per song, it helped drive high profits for iPod sales, contributing to Apple's overall success.