This Home Media Retailing article is about TV shows that get one or more seasons released on DVD, but are then abandoned due to low sales.
The most frustrating ones are the ones that get two or even three seasons out, creating an expectation that all the seasons will be released, and are only then abandoned. That's what happened with "Taxi" -- three seasons came out, and then the studio apparently gave up with only two seasons (and only one good season) left to go. The article indicates that if a season's sales drop off more than 30% from the last one, the series gets the axe. Most annoying.