Nicor Gas only makes actual meter readings every other month. In between the actual readings they make an estimate and bill you according to that estimate. It seems to me that when natural gas commodity prices are falling (as they are now), Nicor makes every attempt to over-estimate your usage so as to get you to pay a higher price for the gas. When prices are rising, however, they underestimate your usage and then you must make it up at the next actual reading after prices have crept up a little higher. This last month their estimate wa... read full review »