I think you remember that term for upgrading to Quicktime Pro which was mandatory to download quicktime movie trailers at one time. That is not needed anymore since Apple requires you to have iTunes installed on your pc to convert your purchased music to mp3 and also to just view the movie trailers on their site.
There are other ways to convert those aac files to mp3 but I haven't tried them since I have iTunes.
This message was edited 2 times. Last update was at Dec 02. 2014 13:33