1. A computer-implemented process for determining expected base sales for a sold product, comprising: obtaining sales data for a product sold at a point of sale location, the sales data organized in a time series according to a time period; obtaining causal data identifying a promotional event for at least one of the product and the point of sale location; excluding sales data corresponding to the promotional event to determine a time series of non-promoted sales data for the product; processing, using a processor, the non-promoted sales data using a double exponentially smoothed moving average model including a smoothing constant that assigns exponentially decreasing weights to older sales data values as the sales data becomes older in time, the processing comprising: executing a preliminary backward pass through the remaining sales data; executing a preliminary forward pass through the remaining sales data; averaging the preliminary backward pass and the preliminary forward pass; updating the remaining sales data for the product based on second sales data for an additional time period received for the product to provide updated sales data for the product; executing an updated backward pass through the updated sales data; executing an updated forward pass through the updated sales data; and averaging the updated backward pass and the forward pass; generating, using the processor, expected base data for the product based on the double exponentially smoothed moving average model; and outputting the expected base data for the product to a user.