Designing E-Commerce User Interfaces

Abstract

E-commerce is growing rapidly. In the United States (US) from 2002 to 2007 online sales increased at a rate of over 23% each year (US Census Bureau, 2009) and annual e-commerce sales are now about $204 billion (Nielsen, 2008b). The percentage of US retail sales that are made online also increased from 2.8% to 3.2% (US Census Bureau, 2009). By 2012, US e-commerce annual sales are expected to be $229 billion (Poggi, 2009). Worldwide, 85% of people with Internet connections have made an online purchase, representing a 40% increase in the past two years (Nielsen, 2008a). More than half of Internet users now purchase from an e-commerce site at least once a month (Nielsen, 2008a). In 2012, almost $1 trillion may be spent annually worldwide on e-commerce purchases (BuddeComm, 2008). By providing quick, convenient access to products, product information, and prices, the Web is turning products into commodities. The ease of use of e-commerce sites is a way to increase customer satisfaction, differentiate a site, increase market share, and enhance a brand (Manning, McCarthy, & Souza, 1998; Tsai, 2009a). Seventy-nine percent of users named easy navigation as the most important characteristic of an e-commerce site (Lake, 2000). Poor navigation and a long and confusing checkout process were some of the reasons people gave for abandoning their shopping carts (Global Millenia Marketing, 2002). When an e-commerce site is easy to use, sales can increase. For example, after improving usability, a major retailer got a US$3,000,000 improvement in annual revenue (Spool, 2009), IBM got a 400% increase in sales on IBM.com (Battey, 1999; Tedeschi, 1999), and Digital Equipment Corporation reported an 80% increase in revenue (Wixon & Jones, 1992). By making the products easier to access, removing unnecessary graphics, and making product information easier to scan, Liz Claiborne’s Elisabeth.com tripled the rate at which lookers became buyers (Tedeschi, 2002a). Competing sites are only a click away. An e-commerce site that is easy to use can build consumer loyalty (Najjar, 1999). Loyalty is essential. Two of every three online sales are made by consumers who knew where they wanted to make their purchases (ActivMedia Research, 2000). Sixty percent of users mostly buy from the same e-commerce site (Nielsen, 2008a). For example, on Zappos.com, 75% of purchases are from returning customers (Wroblewski, 2009). Once users start buying online, they increase the amount of their purchases each year (ePaynews, 2003a, 2003b; Hansell, 2002).