Could also be due to the added weight of your ego? //content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gifOr it could be the massive magnetic field being generated by the motor that is actually causing the Earth to tilt ever so slightly and thus causing the scale needle to move slightly higher.
No, wait, those are the Funky Pups I'm thinking about...