Abstract: A method of estimating daily sales volume includes calculating a day of the week specific projection factor based on reference sales history data in conjunction with an overlapping sample of current day of interest sales data. A sampling of sales data for a current day of interest is acquired and at least a portion of this data are scaled by the day of the week specific projection factor to determine an estimate of daily sales volume for the current day of interest. The portion of data which is used can be from the intersection of sources providing both reference sales history data and current day of interest data. The method provides for an accurate estimation of current daily sales based on a relatively small sampling of current day sales data. The method can be performed in a computer system coupled to a computer network for acquiring the sales data from a large number of retail points of sale.