Here is a list of several popular social bookmarking sites. There are many more out there. However, I have posted more than enough for you to get started with. Some are niche specific and others are more general. Find and use the ones that will work best for whatever you are trying to promote.
BibSonomy – Specifically designed for researchers to share bookmarks and bibliographies, it’s run by Knowledge Data Engineering Group at the University of Kassel, Germany.
Blinklist – Launched by Mindvalley, they are focused in three areas: Technology, Media, and Marketing. Blinklist has a user-friendly interface. In addition, they quote “fully profitable” on their site. So, you can label and comment about any web page on the Internet.
BlogBookmark – Designed specifically for Blog hunters, BlogBookmark claims to have the hottest news, gossip, and blog chatter from around the web. I highly suggest that mainstream bloggers bookmark their entire sites here.
blurpalicious – It’s not too different from other social bookmarking sites, but with a tagline of “Get Blurped!” it is definitely a place to post more light-hearted and fun sites rather than serious or sales sites.
CiteULike – This is a free service that you can use to share, store and organize any academic papers, articles, or information you are reading.
Cloudytags – This is a cool site to which you can submit your links. Cloudytags then analyzes your page and suggests the tags your site is displaying. Definitely, submit your links here.
delicious – THE social bookmarking site. It allows you to easily add sites you like to your personal collection of links and to categorize those sites with keywords. Not to mention that if enough people save your site in a bookmark, it will make their popular page thereby sending you a lot of traffic. Delicious is owned by Yahoo and is a MUST for your social media and bookmarking strategy.
Diigo – This is social bookmarking on steroids. Get an account and start using it. Enough said.
Digg – The social news site that changed the Internet, Digg is a very high power authority and a listing in Digg for a site, even if it only has a couple of votes, will rank highly on Google and other search engines for certain terms. If your site is shared and voted upon on Digg, and makes the Digg homepage, you’ll get a lot of traffic and attention from other bloggers who read Digg.
Folkd – Similar to Reddit, Folkd is a place where you can post pages, news, audio, video, and blogs for the world to see.