We're noticing a lot of demand from clients to deal with their iTunes Match account. Having looked into the details of the service, and also having experience of services such as Spotify, I can see why it's popular.
What is iTunes Match? OK - Match is a service which looks at the contents of your iTunes music library, if it sees music you have there it will make it available to other compatible devices. If those devices (max 10 in total) are computers (Apple or Windows) you can download a copy of that track, if the device is an iPhone you can stream your music. Streaming is the same as listening to your own music as if it were being played over the radio.
Confusingly Apple is now making available copies of purchased music via your iTunes account (at least if you look at the Apple USA website, my music isn't showing up in my iCloud account here in the UK). Very different to iTunes Match.
The way Match works is if a track is both in your library and iTunes Music Store Apple makes that track available to you instantly. So if you've got a cruddy old MP3 version of The Rolling Stones, good news, you'll have access to a much better quality new 256 Kbps version. Anything that doesn't Match - ie music you have ripped that iTunes Music Store doesn't hold - will then be uploaded to the cloud. That will be streamed to you later.
Match is a great service. It provides a pretty quick online backup / archive of your music. It enables you to get hold of your music on other devices, in other places, very easily. For many people you'll get a quality boost along the way too. Downside? Well, if you stream music to an iPhone while out and about check charges for data downloading.
