Server logs report activity on the server and not user activities; therefore they suffer from inaccuracies created through caches, located at various places between the web server and the visitor [31]. Caches are used to reduce response time by storing a web page and providing this page when requested directly from the cache instead of requesting it from the server. Pages shown from cache are not recorded in the server log and the derived measures would underestimate actual traffic [32, 33]