How often would you Bookmark?
Social bookmarking helps a lot in providing exposure to your site. Sharing a few comments and showing off what you have or even simply wanting to share something you came across on the web goes a long way.
Social bookmarking can help your site or make you a referrer to a site that you love to visit. Either way, you are sharing information over the web and helping people needing it in the process. Comments and reactions are important as well. Insights are something important since not all information on the web will always bring positive remarks especially from the critics.