Is bookmarksubmissions is useful in linkbuilding.

yes social bookmarking helps to create back links and also improves the ranking of the site. It is an off page optimization technique.

According to me, Bookmarking content best rules are content should be unique and specifics title for website or website page. It is best way for back links and gets more traffic and it is the greatest off page activity in SEO. If you want your back links are indexed fast so, you can do superiority social bookmarking in High PR sites.