Social bookmarks

In their simplest form, social bookmarking websites are online services that allow users to add, annotate and share bookmarks to various web resources. These bookmarks can be shared publicly or kept private to the user who added them. Social bookmarking websites have existed on the web in one form or another since the mid 90s, with the launch of itList in 1996, and WebTagger (developed by the Computational Sciences Division at NASA) launched in 1997.

Rather than simply adding bookmarks to a browsers local bookmarking system, social bookmark websites allowed users to store and share their bookmarks in what would now be called ‘the cloud’.

As many of these bookmarks were publicly accessible they generated another (user submitted) link into a web resource that search engines could find, follow and interpret.


The most famous (pure) social bookmarking website is Delicious, launched in 2003, and is recognised as coining the term ‘social bookmarking’. The difference between Delicious and

The success of Delicious at this time led to a host of other social bookmarking websites launching, such as Furl, Simpy,, Ma.gnolia, Mister Wong and Diigo to name a few.

Similar to web directories, a critical mass of sites where link builders could place a link to the site they were optimising for was beginning to form.

Digg & Reddit

Digg (launched in 2004) and Reddit (launched in 2005) technically (in their original form) are also both social bookmarking websites. The difference with these sites is that they also contained more complex voting systems allowing users to up (or down) vote submitted resources (rather than just submitting the resource again as a form of a vote). These sites also more actively encourage discussion and commenting about the submitted resource.

Pligg & the rise of bookmark spam

Pligg (launched in ) is a piece of website software that allows anyone to add a Digg like clone to their website. In the same fashion that WordPress allows the quick and easy installation of a blogging platform, Pligg offers the same functionality but for ‘social bookmarking’.

The available of such software led to an almost endless plefora of social bookmarking sites being launched, some focused in on niche topics, others all encompassing. The vast majority of these sites were/are of poor quality, with few real user submissions and little equity of their own. Many, if not most of these sites were abandoned by their owners and not actively maintained or updated. Most of the social bookmarking sites can be viewed as low quality websites. Depending on the age of the install, and the nature of the bookmarking site, some of these sites will add the nofollow attribute to the relationship attribute within the submitted link, though many do not.

The mass proliferation of both Delicious and Digg clones led to an almost endless amount of social bookmarking websites live on the web. A good portion of these sites had a clear footprint left by the Pligg software. This has led to social bookmarking websites being a prime target for blackhat SEO link spam software.

The pattern of the growth of web directories, and the subsequent mass spamming of them to generate link equity, was aped by social bookmarking websites. Both are examples of website types that were originally created as useful web resources but were abused by SEO consultants to generate incoming link equity to manipulative search engine ranking positions. Many of the links placed onto social bookmarking websites would make use of commercial anchor text.

As such, these auto generated spammy links are viewed as manipluative by Google.

Social bookmark link action

In the majority of cases social bookmarking links should be disavowed. They are links on low quality websites, often surrounded by other manipulative links, utilising commercial anchor texts on unmaintained websites.

There are exceptions to this. Links on high profile, legitimate, websites (such as Delicious and Reddit) that have been naturally submitted can remain as part of a non-manipluative link profile. Other niche active social book marking websites, focus in on particular topics, can also have value and should be retained.