This document summarizes information about estimating the impact of advertising expenditures. It begins by asking the reader to estimate unit sales for a typical firm that sold 50,000 units last year with $1 million in advertising, and plans to spend $1.1 million this year. Most studies have found the average advertising elasticity is around 0.1, meaning a 10% increase in spending yields a 1% increase in units. Therefore, the estimated unit sales for the coming year would be 50,500. The document then discusses how elasticity and effective advertising levels vary based on product type and media channel. It concludes by introducing Wright's Rule for determining the optimal advertising budget based on elasticity, gross margin per unit, and forecast