I can see there is some guidance on transferring profile data from one version of (say) Firefox to another. What I don't understand is why you would want customers to jump through such hoops. I have a Linux system for which I have backups and I can tell Firefox or Thunderbird where to find the data so why can't I just say Import address book from Thunderbird here...... OR Import Bookmarks from Firefox there...... It should, surely, be a lot easier to import data from files you already understand into your own profile, rather from everyone else's file formats?