iTunes Match is a paid service that, in my opinion, is very worthwhile althoug it flies under the radar. For $25 a year, Apple will host your personal iTunes music collection on their servers, irrespective of whether you purchased the music through them. I uploaded my entire music collection, nearly all imported from CDs, and now all of my songs and playlists are available on my work computer, phone, and tablet. Music used to use up the most storage space on these devices. Now, I have bought less storage in all of my new mobile devices: 16GB iPhone, 16GB iPad, and 256GB MacBook Air.