The web sites of libraries are to a large extent their public face and to help market their services, the web sites must have interesting and regularly renewed content. They must also be visually attractive and easily used, and thus be well structured and have a well functioning navigational system. The web masters' awareness of the ability of web sites to attract users to the site and also to the library, as well as their knowledge of suitable content and site construction, is crucial for how successful the web site actually is at marketing the library. The research question is: How do the studied web sites function as marketing sources and service providers for the libraries, and are the web masters aware of the importance of the web site? The purpose is to investigate how the library personnel looks upon the web site as a possible way to increase the popularity of the library among the public, and to study the construction and content of the library web sites to find out how well these serve their purpose. The result shows that the web sites meet the demands of interesting content as well as attractive and simple construction to a certain extent, but there is still more to do to make them even better. The web masters are aware of how the structure and content should be in broad outline, but say that there is lack of time and means. The purpose of the web site is for example to simplify the use of the library, to convey quality information, and to market the library. Some of the web masters already see the web site as an important marketing tool, while others only see it as an information source about the library.