According to my iPhone, I made over 12k steps today just since 5:30 PM (when I updated my iOS software). That did include a 2.5 mile walk as well as one mile on the tread mill and one mile on the elliptical. It said it was about 6.5 miles altogether, so my walking to the car after work, walking around the house and playing with the kids was worth 2 solid miles? There is no way that is accurate.
My normal steps when I don't work out average 2 miles , from house to car, work parking spot, mailbox, walking around at work, etc... I think it's legit but I don't think it counts as "exercise"