Destinations emerge as umbrella brands that need to be promoted as one entity for each target market they try to attract in the competitively fierce world of travel and tourism. A Destination Marketing Organization (DMO) plays a crucial role in the promotion and management of a tourism destination, mainly through an effective use of its Destination Marketing System as a marketing tool. Due to the fast growing importance of the Internet as an information and communication medium, these systems have been modified in order to be Web-based. However, it is no longer enough for a DMO to just have a Web site. Successful Web Marketing requires an articulated approach to three critical tasks: web site design, promoting the web site, and assessing the web site marketing effectiveness. This paper aims to provide a set of useful guidelines required for DMOs to achieve successful marketing on the Internet. In order to offer empirical evidence of the Web sites that fit within the guidelines provided, official Web sites of ten European DMOs were analyzed.