Social bookmarking allows users to save, organize, and share bookmarks of web pages. Popular social bookmarking sites include StumbleUpon, Delicious, and Digg. StumbleUpon uses a toolbar and ratings to recommend websites to users based on their interests. Delicious allows users to tag and share bookmarks publicly or privately. Digg allows users to discover and discuss content by submitting and rating stories. The advantages of social bookmarking include consolidating bookmarks across devices and sharing bookmarks with others. However, inconsistencies in tagging vocabulary can make some bookmarks difficult to find.