Clearly this mattress pad wasn't any kind of necessity but for my boyfriend it was something that made a huge difference for his sleeping, even if it didn't do much for mine. He rested better and didn't complain about being cold, it soothed his muscles, etc. But I would also argue (and have) that a hot bath before bed and an extra layer of pajamas could probably accomplish the same thing and not have to be plugged in.
Do you have unnecessary necessities at home, or does your partner/roommate have one?
(For those that are curious, we got the Sunbeam Rest and Relieve Therapeutic Mattress Pad on sale at Target.)