The dirty tricks of online shopping, designed to make you spend more

As millions of people begin their holiday shopping, they'll come across many familiar tricks online. In some cases, sites will hype limited-time deals with a countdown clock, warn you that the product you're looking at is running out of stock, or tell you that 65 people in your area have recently purchased the item. In others, they'll quietly add items to your cart, or sign you up for recurring payments under the guise of a free trial. Many of these manipulative retail strategies have existed since long before the internet-think of the store with the never-ending "Going Out of Business" sale, or the Columbia House "8 Albums for a Penny" deal. But online shopping has pushed these shady practices into overdrive, deploying them in newly powerful and sneaky ways. In a first-of-its-kind survey, a group of University of Chicago and Princeton researchers found that "dark patterns" on shopping websites were startlingly common-appearing on more than 1 out of 10 sites and used frequently by many of the most popular online merchants. "'Dark patterns' are basically tactics a user interface design uses to lead a user down a certain path for the benefit of the service provider," said the paper's co-author Marshini Chetty , assistant professor of computer science at UChicago, whose research explores the effects of internet design and practices.