ABSTRACT
Social bookmarking services (SBSs) allow users to store and organise links to interesting websites and, crucially, share them with others (the social aspect). Essentially, they replicate the process of bookmarking webpages, which all browsers oer, but add the functionality not only to share them with other people but also, since they are stored remotely, to access the same set of bookmarks from dierent computers. During the storage process one can usually organise and categorise the bookmarks in various ways and an important component of social bookmarking is to be able to store and share metadata about a website.
