If you have web site or blog and if you do not wish to get new visitor/traffic to your site then you may avoid social bookmarking. But social bookmarking help you to bring targeted traffic by using related tag category.. beside that it create backlink for your site which help your site to increase backlink.

• Quality backlink  is popular whitehut off page SEO method by bookmarking you get quality baclink
• Targeted traffic which you will get by social bookmarking "tags , catagory"
• "Branding" If you regular update your site & bookmark it to popular social bookmark sites then it will help to create branding of your site.