An search engine optimisation ethos that avers that it is legitimate to take advantage of flaws in search engine algorithms to achieve good rankings for keywords - thus going outside the guidelines issued by the search engines themselves.

Search engine rankings are the result of a complex interaction between search engine software (the algorithms) and pages and domains available on the internet.

With billions of web pages available to the search engines, and technology changing all the time there are inevitably shortcomings between what the search engines are aiming to do (list high quality, relevant content) and what they are capable of doing.

Black Hat SEO aims to seek out the reasons for these shortcomings, and exploit them to gain good rankings.

"Train scripts": An Example Black Hat Technique

The popular social media site MySpace has had some of the most impressive traffic levels of any site on the internet over the past 2 years. Users can create a personal profile, maintain a blog, list their interests and hobbies and make 'friends' among other MySpace users.

Users can also link to their own websites.

Because the site ostensibly relies on real people, the search engines would see a link from MySpace as a legitimate link. If someone has a profile on MySpace and they've linked to a site, then it was assumed that that link would reflect a real interest on the part of a human - exactly the kind of thing a search engine likes to see.

Unfortunately, MySpace's signup process could be circumvented by automated scripts known as 'train scripts'. Black Hat SEOs created fake profiles that essentially acted as a link back to the site they were promoting.

By this process, it was possible for Black Hat SEOs to generate higher profiles for their customers' sites through association with thousands (or even millions) of 'human' links.

Further Reading

• Black Hat vs. White Hat
  Information from Wikipedia on the ethics of Black Hat techniques.
• Black Hat Resources
  Resources, links and further reading for those interested in Black Hat techniques.
• Information for Black Hats and Spammers
• David Naylor
  Blog maintained by one of the leading Black Hat SEOs.