For something in the low cost range, adding a pressure mat sensor can open up a lot of possible use cases you might not have considered:
Halloween tricks
Know if the dog is in his crate
Instant on for the Disney Channel
Control lighting when someone gets on or off the couch
Be alerted when the dog is waiting to go in or out
Wanderer alert to activate at night and be alerted if any household member starts to go outdoors before they get the door open