1. An internet website which presents a hierarchical menu structure to users, the site having a default menu structure and means to automatically modify the default menu structure for each user over time, wherein the modifying means includes means for providing, as at least one additional menu option for a particular menu page, at least one link which is similar, as determined by a predetermined similarity measurement, to at least one menu option present on the particular menu page other than through the similarity measurement, the similarity measurement being a function of that and other users' browsing history.