Yesterday, Steve Jobs announced many new things (iOS5, Mac OS Lion, iCloud…). Among them, there is one that interested me: iTunes Match. Here is the description you find on Apple’s site:

If you want all the benefits of iTunes in the Cloud for music you haven’t purchased from iTunes, iTunes Match is the perfect solution. It lets you store your entire collection, including music you’ve ripped from CDs or purchased somewhere other than iTunes. For just $24.99 a year.

Here’s how it works: iTunes determines which songs in your collection are available in the iTunes Store. Any music with a match is automatically added to your iCloud library for you to listen to anytime, on any device. Since there are more than 18 million songs in the iTunes Store, most of your music is probably already in iCloud. All you have to upload is what iTunes can’t match. Which is much faster than starting from scratch. And all the music iTunes matches plays back at 256-Kbps iTunes Plus quality — even if your original copy was of lower quality.

Thus, Apple most probably uses an audio fingerprinting technology that identifies a song, and then Apple proposes in iCloud the same song with top quality. Although the site describes only songs that “you’ve ripped from CDs or purchased somewhere other than iTunes”, in fact it will also work for illegally downloaded songs! In other words, for 25$ per year, you switch to the legal side (at least if I understood well that the service does not oblige you to purchase the songs).

There is no free lunch (or near free lunch). Where are the limitations?

• There is an upper limit on the number of songs.
  

  Limit 25,000 songs. iTunes purchases do not count against limit.

  This is probably not too constraining. 🙂

• The upgraded songs are accessible as long as you subscribe to the service; Would you cancel it, then you will loose all songs that were not purchased through iTunes.
• It is not clear to me, if the scanning is done only once when you subscribe to the service, or continuously. If it is the first case, then you will have to purchase new songs through iTunes to enlarge your collection in addition to the subscription. If it is the second case, then there is an obvious method to enlarge your collection with only the price of the subscription. You “just” have to download the illegal version of a song that iTunes Match would then replace by a legal one.

Whatever the answer for the scanning frequency, it is an interesting answer against piracy. Furthermore, it is a marvelous way to lock-in the customers. Once you start to use such a convenient service, you cannot switch back to a less convenient one. In other words, you’re locked in (see Dan Ariely’s book “Predictably Irrational”).

If someone has the answer to my question, please tell it. It makes a serious difference in the cost analysis for customers.