Google Music keeps the tunes playing

I started using the new Google Music production service.  I hadn't explored Google's previous offering, the Music Beta, all that much, but decided the time was right to dip a toe into the water.

The service has a lot of similarities to iTunes, of course, except one's library is in the cloud rather than on a PC (assuming one isn't using Apple's iCloud).  Google gives one free space to store 20k songs.  I'm using about 1% of that quota so far.

I like the idea of having a copy of our music in the cloud as an additional backup (or preservation copy), and it is also nice being able to use a standard browser window to manage and play the music.  One complaint I have about iTunes is that because it is conventional desktop software, one has to update it from time to time.  And this is somewhat more burdensome if one has to switch from a "standard" type of login on Windows to one with administrative rights, and then switch back again.

Google provides a tool which will copy music from one's existing storehouse (mine was an iTunes library).  The tool worked well for this purpose, and it did NOT require any administrative rights on my home WinXP (I know, I know) to download, install, and execute.  I started the copy one evening, and some 400 songs had been copied into Google Music by the morning.  One feature request:  It would be fabulous if the Music Manager tool would pull songs directly from a CD.

On the back-end I wonder if Google is using some form of de-duplication to minimize the amount of storage it needs to provision for this service?  It must be the case that there would be great overlap between music collections, particularly with the most popular songs, artists, albums, etc.  Google does such a good job of squeezing storage efficiency out of GMail; would expect them to do the same for their music service.