Hey..
Guys what do you think which is best one for fast optimization.. social bookmarking sites or social networking sites..
As far as i think both are good

Social Networking can drive huge traffic on site and also increase authority of site, product & service.
Social Bookmarking also increase traffic and get backlink for your site.

Social networking sites allow users to create a profile, providing photos, website links, biography information, or a host of other personal details. Users can view other profiles, connect in forums, or comment in community chat rooms. Social bookmarking works best when users also take the time to get to know other members. Many sites rank the popularity of articles by the number of votes they get from their members, so it pays to get to know other users. Unlike a social networking site, however, members are limited in the items they can post.