DVD on TV, that's fine. TV on DVD, time to buy a new DVD.
OK, that was pretty bad. Let's try this one again.
When television shows get so old that even the most struggling of cable networks and local affiliates won't air them, producers will usually re-issue the shows, in an expensive box set, at the local huge electronics or department store near you. They then make big advertisements calling the show a "long lost classic" or some other baloney like that. Strangely enough, it sometimes works and the show is said to have been "rediscovered by a new audience," or some other boilerplate like that. The producers receive a windfall that they promptly use to make box sets of 3 or so other forgotten old shows.
Naaah, the first one was better.