I thought they just got stats from the power companies that measured power spikes when everyone got up to make a cuppa when the ads came on.... and multiplied that by 2 and half kids and a dog.
But that was last century (before heat-pumps). Now apparently they just monitor when your fridge light comes on as this caters for the more eclectic beverage mix. If you want to skew their data, buy a 2nd fridge.