The phenomenon of impulse purchasing, while extensively researched, has yet to be explored in online retail environments. However, in the modern-day market, where many consumers, particularly young people, do most of their shopping over the Internet, this is where the majority of spontaneous buying seems to occur. Survey research was employed to collect data about online impulse purchasing amongst a sample of 484 consumers from around the world. Subjects were measured for general tendency to make purchases on impulse using 20 cognitive and affective items from the Impulse Buying Tendency Scale (IBTS) (Verplanken & Herabadi, 2001), and then asked if they had exhibited this behavior at large-scale online retail stores, such as Amazon.com. The 244 subjects who admitted to doing so were asked another series of 20 questions regarding the motivation behind their purchasing decisions. Probit regressions were used to determine the effect of demographics on likelihood of making impulse purchases online and to explain this behavior within the context of the IBTS. These act as supplementary evidence to the two main OLS models, which were used to determine the correlation between different site features and consumer tendencies that influence site design respectively, and tendency to buy on impulse amongst online impulse purchasers. The results show that many features and aspects of design of online retail websites are successful in inducing impulse purchasing via the satisfaction of common consumer desire for simplicity and instant gratification in making purchases.