For organizations engaged in electronic business, the corporate website has emerged as the single most important interface through which transactions are carried out. This being so, appropriate design characteristics are required to make websites effective. Customers expect websites to be designed differently, depending on the task and purpose associated with the website. This paper identifies and analyzes important characteristics of the 40 most successful websites from five different categories: Retail, Financial Services, News & Information, Search & Portal and Entertainment. The findings indicate that there are six critical characteristics of websites and the relative importance of these characteristics varies across categories. The paper explains these results and based on them, develops managerial implications and guidelines for website design.