Social bookmarking lets Internet users save, organise, search, and manage bookmarks of websites or web pages they want to remember or share. This relatively new term, along with tagging, was coined by web service Delicious in 2003, although the concept of shared online bookmarks goes back as far as 1996. Occasionally, social bookmarking is referred to as social book marketing, because its popularity as an online marketing tool or strategy has grown tremendously with a burgeoning number of new book marking services emerging. Coupled with search engine optimisation, social book marking is fast becoming a key strategy in an online marketing campaign.

The focus of search engine optimisation or SEO is to create brand awareness through better search engine rankings. With the fight for higher rankings being the fundamental idea behind SEO, social book marking is quickly seen as a good SEO tool for back links and better PR. Book marks generally use tagging, a bottom-up method of representing a link. Thus, as opposed to a hierarchical structure, tags create broad (and multiple) categories that links could fall into. The SEO advantage of this is it allows the metadata that adds relevance to the links to be asserted by users of the content. The marketing appeal is similar to a "word of mouth" campaign, where product or service validation comes from friends, family or an authority of sorts.

Now the tags are wonderful for SEO, since they work similar to keywords. Tags, and the link they added to, are indexed at the same time by most search engines. Thus, any content that you supply to a social book marking service will add your links with the relevant keywords appended. As a result, no only do you receive links from high traffic web sites, but highly relevant as well as peripheral searches will generate your website. Popular search engines' web spiders regularly visit large book marking websites and if new web pages are added here, they are guaranteed a quick indexing.

Social book marking, in addition to providing an SEO benefit, can also be a marketing tool in its own right. Seeing as users can adapt popularity rankings of bookmarked links by approving, disproving and/or rating them, viral marketing campaigns can flourish over these web services. SEO firms looking for social media optimisation can tap into well established users to ascribe their authoritative assertions to web pages or services added to the book marking website. However, optimisation is tricky with the danger of negative reviews or rankings ever-present. Worse yet, your book marking account and website could be branded as spammers if the links you submit have no relevance to users.

Social book marks have evolved past the phenomenon they were a few years ago. SEO firms and online marketing companies agree that the benefits social media brings are manifold and most certainly cannot be ignored.