A new study by Paul Hoban, assistant professor of marketing at the University of Wisconsin-Madison’s Wisconsin School of Business, and Randolph Bucklin of UCLA’s Anderson School of Management, suggests that if you are targeting consumers simply because they have spun through your Web site like wind through the trees, you might as well toss your money into the wind, as well. Rather, the best display ad ROI is to be had from targeting people who are new to your site, or have been there and done something.