One time that download protection could have been useful (though I didn't purchase it and luckily the company was kind enough to help me out)...
I purchased a program quite a while back for my old XP machine from Raxco (http://www.raxco.com
). For an additional price, I could have added extended support, download, and upgrade protection (for major updates). During the time I was using it, a few minor updates came out for new functionality and bug fixes. An update came down the pipe at one point that made the software Vista compatible. Eventually, Raxco stopped selling the program, and stated that they would provide support for any users who had purchased the extended support, upgrade, and download service. Fast forward a few months, and I bought a new PC with Vista. The original installer that I had archived for the program would not install at all under Vista. The upgrades, including the Vista compatible version, I had downloaded were not standalone installers. If I had the extended support and download protection, I would have been able to log into the site and download a Vista compatible installer without a hitch. Fortunately, the vendor has exceptional customer service, and when I contacted them to ask if there was any way they could help me out, they immediately provided me with a link to download a compatible installer. They also offered to provide any customer support I would need to get the program up and running on Vista.Disclaimer: I am not affiliated with Raxco, nor do I receive any compensation for any sales that this post generates. I am simply one of their customers who has been consistently impressed with their professionalism and customer support.