To improve the quality of healthcare, we offer access to high quality guidelines to physicians as well as information harmonized with these guidelines to concerned patients via internet. We launched this service in 1994. Since then, we have been offering user-friendly access to the NCI's CancerNet via WWW (http://www.meb.uni-bonn.de/). Among other information, CancerNet by the National Cancer Institute contains up-to-date summaries on the prognosis, staging, and treatment of more than 80 major tumor types. To obtain information about how users navigate through this service, all users' activities are logged by using cookies for tracking them without injuring privacy. To get additional information about our users and their interests regarding our service, we performed user surveys in 1996 and 1997. The analysis of 538 valid answers in 1996 and 1001 in 1997 show that the attempt to bring high quality information and guidelines to physicians and patients was successful. About 95% of our users rated our service "excellent" or "good".