Space Dicks was a sub where men would post photos of their dicks. These were no ordinary dicks though, they were heavily altered. Like a dick flayed open like a split hotdog, crazy piercings, implants... it was just not a pleasant sub to stumble upon.
Some times this happens because they are only allocated so much supply to produce the item so if it is popular it will sell out before the run end date, and inversely if it is not popular they will try to sell as long as they have the material to do so to recoup the food cost.