I've recently noticed that even digital purchases (in the sense of a DRM-free download) aren't absolutely perfect in that regard – the lack of a working second-

I've recently noticed that even digital purchases (in the sense of a DRM-free download) aren't absolutely perfect in that regard – the lack of a working second-hand market for digital downloads means that a work being pulled from distribution is more or less guaranteed to instantly become completely unavailable (at least legally speaking – if you're lucky you can still find it under the table through less reputable sources) from one moment to the next. With physical media on the other hand first of all stopping distribution doesn't automatically mean recall of all existing stock from all shops, and in any case there's also the second hand market to completely legally fall back to.