The title of this article is conjectural. Though the topic is found within The Simpsons universe, a proper name is not available.
The Vend-A-Couch couch gag is the eighth couch gag of Season 8.
The couch is replaced with a coin slot and the words “Vend-A-Couch” written on the wall. Homer decides to put a coin in; nothing happens. Homer pounds on the wall four times before the couch falls on him. He then says, "D'oh!"