Introduction

On a Social Bookmarking system or network, users store lists of Internet resources that they find useful. These lists can be accessible to the public by users of a specific network or website. Other users with similar interests can view the links by topic, category, tags, or even randomly.

Other than web page bookmarks, services specialized to a specific subject or format - feeds, books, videos, music, shopping items, map locations, wineries, etc. - can be found. Social bookmarking is also part of social news sites like Reddit.

Overview

In a social bookmarking system, users store lists of Internet resources that they find useful. These lists are either accessible to the public or a specific network, and other people with similar interests can view the links by category, tags, or even randomly. Some allow for privacy on a per-bookmark basis.

They also categorize their resources by the use of informally assigned, user-defined keywords or tags (see folksonomy). Most social bookmarking services allow users to search for bookmarks which are associated with given "tags", and rank the resources by the number of users which have bookmarked them. Many social bookmarking services also have implemented algorithms to draw inferences from the tag keywords that are assigned to resources by examining the clustering of particular keywords, and the relation of keywords to one another.

Its increasing popularity and competition have extended the services to offer more than just sharing bookmarks, such as rating, commenting, the ability to import and export, add notes, reviews, email links, automatic notification, feed subscription, web annotation, create groups and social networks.

Advantages and Disadvantages

This system has several advantages over traditional automated resource location and classification software, such as search engine spiders. All tag-based classification of Internet resources (such as web sites) is done by human beings, who understand the content of the resource, as opposed to software which algorithmically attempts to determine the meaning of a resource. This provides for semantically classified tags, which are hard to find with contemporary search engines.

Additionally, as people bookmark resources that they find useful, resources that are of more use are bookmarked by more users. Thus, such a system will "rank" a resource based on its perceived utility. This is arguably a more useful metric for end users than other systems which rank resources based on the number of external links pointing to it.

On the other hand, there are drawbacks to such tag-based systems as well: no standard set of keywords (also known as controlled vocabulary), no standard for the structure of such tags, mistagging due to spelling errors, tags that can have more than one meaning, unclear tags due to synonym/antonym confusion, highly unorthodox and "personalized" tag schemas from some users, and no mechanism for users to indicate hierarchical relationships between tags Social bookmarking can also be susceptible to corruption and collusion. Due to its popularity some users have started considering it as a tool to use along with Search engine optimization to make their website visible. The more a web page is submitted and tagged, the more chances it has of being found. Spammers have started bookmarking multiple times the same web page and/or each page of their web site using a lot of popular tags, hence obliging the developers to constantly adjust their security system to overcome abuses.

Starting in April of 2007, developers of popular spamming tool named Trackback Submitter, released new software to spam all popular social bookmarking sites automatically. Social Bookmarks Submitter helps spammers to automatically create new accounts and promote their websites by tagging URLs multiple times under different usernames. New spamming software became so popular between lovers of black SEO, that some social bookmarking websites (supported by Social Bookmarks Submitter) were forced to add CAPTCHA protection against spam, which caused some problems for people who use social bookmarking for non-spamming purposes.