Matt Deangelis writes about how social bookmarks are on of the tools for spreading word about your product or service virally.

Social bookmarking sites allow users to create a set of content bookmarks. These bookmarks are organized by tags, which are (usually) arbitrary words or phrases the user can assign to content. This gives the user a way to classify, rank and organize content using tags. The most popular Social Bookmarking Site is del.ici.ous, which has millions of users.

What is the strategy for bookmarking your site?

1. Write good content that people like to bookmark, such as lists, how-to’s, technical articles and humor.
2. Provide people with the tools to bookmark your content, such as the following bookmarking websites, such as del.icio.us, Listible, Digg, StumbleUpon, BlinkList, Spurl, Magnolia, Furl, BlogMarks, and Reddit.  There are also a lot more social bookmarking sites out there, so do your research and make sure you provide your users with the tools for the bookmarking sites that match your content.