That's what a Rimm-Kaufman Group study attempted to find out. Using Digital Element data, the company tied 3 million PPC clicks to their ZIP codes for one data set, and nearly 2 million click-throughs for the other, George Michie explains. He steps through the process of linking the census data with information on location, average household income, population, land area, average age, average home value, number of business addresses, number of residential addresses, and more. The results might surprise you.