Extended Download Service ensures you be able to download (at Member Center > Extended Download Service) the standalone offline installer of nearly each and every history official release, whether minor or major version, anytime later just in case you need to reinstall a particular version of the MusicFab software you've purchased. If you don't choose this service, you can still re-download that specific version when you purchase, but only for a limited period of time until a new version comes out. With only $9.99, that limitation will be lifted for good, you can redownload any official release anytime you want.