Releasing an unfinished, untested, broken and unplayable product for sale aka Fallout 3′s The Pitt DLC:

The initial release was full of floating exclaimation marks, unfinished textures, graphical glitches and became unplayable after a certain point due to the game crashing. How did it get released in such a state? Thankfully Blethesda sorted it after a day or so.