With digital you're hoping the 'store' keeps it in storage for you in perpetuity so you can redownload/stream it. If you buy a DVD and lose it you can't go back for another free copy. There's definitely an issue that the original license should allow you to always download and backup your copy DRM free so you will always have access but most people aren't going to do that. I bought lots of music/video content from iTunes over the years and rarely back it up. The fact I can just stream it/redownload it from them is very useful but it's also unreasonable for me to expect that Apple should be hosting my 99¢ purchase for the rest of time.

> With digital you're hoping the 'store' keeps it in storage for you in perpetuity so you can redownload/stream it.

Not necessarily. What if the store didn't have to do that?