One license:

The registration / activation key is stored on the iPod. The advantage is there's no need to register different computers since it is the iPod that is registered. This is more convenient since most users have one iPod but two or more computers they want to connect to. So you can use your iPod with any Mac you like without having to type in the registration data on every Mac.

“Friend Pack” - two licenses:

This is useful if you also want to synchronize from or to an iPod other than your own, or if you want to gift a license to a friend.

On request, you can buy more than one additional license at the discounted price.

Updates:

Although it didn’t happen in the last 6 years, updates to a higher main version number (for instance version 1.x.x to 2.x.x) MAY cost a little update fee. In reality, the update to version 3.x.x and 4.x.x have been free of charge.

All updates within the main version number are generally free of charge (for instance every version in version 4.x.x). Updating iPod.iTunes is very easy as you can do it from within the application with one single click when a new release becomes available.

Try iPod.iTunes

Further Questions?