Forecasting Sales Using Excel The Excel file associated with this exercise includes weekly data for Clack Inc. including cash sales, number of ad impressions, and number of ad clicks. Ad impressions are the number of times that a digital advertisement is displayed on a person's screen. Ad clicks are the number of times that a user clicks on a digital advertisement. In this exercise, we examine the relation between the number of ad impressions and cash sales and the relation between the number of ad clicks and cash sales. Understanding the relations of ad impressions and ad clicks to cash sales can help us determine if future cash sales can be predicted given future estimates of ad impressions or ad clicks