What Causes Customers to Buy on Impulse?
User Interface Engineering: Impulse purchases represent almost 40% of all the money spent on e-commerce sites, according to recent tests we conducted. What drives shoppers to make these impulse purchases? It isn't price, but rather it's tied to design elements of the site itself. (2001-05-06)
The link address is: http://www.uie.com/publications/whitepapers/ImpulseBuying.pdf