In the first part of this, I discussed VHS and briefly touched upon DVD. The latter has been with us for 20 years and proved to be a financial blockbuster for movie studios looking to capitalize on their back catalogues.
However, sales have dropped and it is interesting to think about why. Young people are not interested in owning physical copies of movies and music, preferring to lead lives less centered around possessions. The advantages to this are obvious, but not if you like to collect films or your favourite tunes.
Buried in the user agreements issued by companies like iTunes is the caveat that you do not actually own files that you buy; they can be taken back from you either after a certain period or with no warning at all. So that copy of STAR WARS: THE FORCE AWAKENS you run for your kids every few months might just be gone when you need it. Not the case with physical media (unless the disc is not manufactured correctly; I have had some dual-layer DVDs and DVD-Rs fail on me after a decade or so).
If you are not the type of person who likes to re-watch things or prefers the sort of rotating variety in your music you can get with a service like Spotify, then physical media will seem like an expensive and space consuming inconvenience. However, one of the wonderful things about DVD (and its successor, Blu-ray) is its ability to hold so much content: multiple versions of a movie, deleted scenes, audio commentaries, making of featurettes, etc. If you truly love a film, then a fully loaded special edition disc can really off an all-encompassing experience. This suggests that discs may last a few years longer, thanks to such cinefiles as myself. However, they will likely become increasingly expensive and more difficult to acquire.