Inside A Black Hat's Toolbox (Second Half)

The second in the two part discussion of some black hat techniques used in the SEO industry.

Although efforts have been initiated by both webmasters and search engines to minimize the effects of content spamming, another technique employed by black hats is in the form of link spamming. Although less obvious in terms of site content, this is nonetheless more troublesome in terms of getting websites into the top ranks of a search engine without any relevance to the keywords used by users.

According to Brian D. Davison, associate professor at Lehigh University, he defines link spam (which he calls "nepotistic links") as "... links between pages that are present for reasons other than merit." Link spam takes advantage of link-based ranking algorithms, which give a higher ranking to a website the more other highly ranked websites link to it. These techniques also aim at influencing other link-based ranking techniques such as the HITS algorithm. This definition gives the disturbing idea that search engines can be manipulated at the algorithm level, which would imply that there is an inherent weakness in the way search engines would filter out unwanted sites.

But what are example of link spams? Below is a list of common techniques employed even until this day:

Link farms – involves creating tightly-knit communities of pages referencing each other, also known humorously as mutual admiration societies.

Hidden links – putting links where visitors will not see them in order to increase link popularity. Highlighted link text can help rank a webpage higher for matching that phrase.

"Sybil attack" – this is the forging of multiple identities for malicious intent, named after the famous multiple personality disorder patient "Sybil" (Shirley Ardell Mason). A spammer may create multiple web sites at different domain names that all link to each other, such as fake blogs (known as spam blogs).

Spam blogs – spam blogs, also known as splogs, are fake blogs created solely for spamming. They are similar in nature to link farms.

Page hijacking – this is achieved by creating a rogue copy of a popular website which shows contents similar to the original to a web crawler but redirects web surfers to unrelated or malicious websites.

Buying expired domains – some link spammers monitor DNS records for domains that will expire soon, then buy them when they expire and replace the pages with links to their pages. However Google resets the link data on expired domains.

Cookie stuffing – this involves placing an affiliate tracking cookie on a website visitor's computer without their knowledge, which will then generate revenue for the person doing the cookie stuffing. This not only generates fraudulent affiliate sales, but also has the potential to overwrite other affiliates' cookies, essentially stealing their legitimately earned commissions.

The techniques mentioned above are some of the most notorious employed by black hats. The negative impacts of these strategies have resulted in failure for search engines to deliver desired content, negative user experience on the part of internet surfers, and the negative image generated for legitimate sites. It is only through long and costly overhauls by white hat SEO have these problems been slowly resolved.