Executive summary Online sports marketing has become the best foundation for building fan communities for professional sports league and teams. With the development of more powerful technologies, access to the internet has increased. Websites are now including media such as audio and video files, podcasts and live broadcasts of league games. More powerful media has also enabled more user interaction and user empowerment. Two key elements in the increasing use of online services to increase the effectiveness of online sports marketing are multimedia and user interaction. Together, they provide an increasingly sophisticated, powerful and user-based medium that offers marketing challenges and opportunities to business organisations including professional sport organisations. Related to improved user engagement is the increasing sophistication of sports websites. Creating value for fans has become more difficult because they want more benefits from online experiences, including the development of social connections. Teams could take advantage of fans' attachment by creating interactive web spaces, extending team experiences and building fan loyalty. In Europe and North America, the world wide web (the web) hosts 234 million websites and has 1.8 billion users. By 2011, advertising revenues from online advertising at sports sites will likely exceed US$1 billion, a three-fold increase since 2006. Many teams have incorporated media-based content and opportunities for fans to interact online with teams and with each other. This study reviews recent literature about the evolution of the web, identifying and discussing opportunities for a sports organisation to increase its fan base and online user interaction as a key marketing strategy. It also investigates use of the web for enabling fan interaction by 12 professional sports teams in four top-tier leagues (hockey, football, rugby, soccer) in North America and Europe. All 12 teams in the sample investigated had established a team website and offered online media-related services and interaction activities for fans. A wide range of offerings was found in the frequency and type of media-related content and opportunities for fan interaction. The National Football League (NFL) used more online marketing strategies and more media-based content than teams in the National Hockey League (NHL), the Premier League (soccer) or the Super League (rugby). Moreover, US sports teams in general surpassed teams in the other leagues in using the web for sports marketing. Teams in the Premier League, NFL and NHL offered the most online services; teams in the Super League offered the fewest. To date, Premier League teams have taken greater advantage of media-related opportunities than other teams. No team website offered all of the categories; thus, many teams could extend the scope of media-related content and opportunities for fan interaction. The results of this study could potentially benefit a wide range of professional sports teams by providing information about the use of online marketing strategies by major league teams. Teams could apply this information to increase revenue, enhance fan loyalty and build the brand of individual organisations. Introduction The world wide web (www) or web has become an increasingly expansive and sophisticated medium of global communication. This immensely large set of documents, or web pages, provides access to a wide range of online documents, products, and services (Dutton, 2005). In January 2010, Royal Pingdom reported that the web consisted of 234 million websites with 1.8 billion users, 418 million in Europe and 253 million in North America. In addition to serving as a source of information, the web has become an important marketing tool. Its worldwide scope provides sports organisations with the opportunity to connect to fans while spending less on advertising (Tomlinson, 2010). …