Wherever you read about search engine optimization you will come across the phrases black hat, white hat and even gray hat. Dictionaries tend to define ‘white hat’ as ‘hero or good man’ and this expression was probably derived from the early cowboy films where the good guys inevitably wore white hats and the baddies wore black hats. Here is a still showing the Laredo Kid (Bob Baker) with the drop on Henchman Joe (Glenn Strange) in the 1938 western ‘The Last Stand’.
White hat SEOs adhere to the letter of the search engine guidelines (Google, Yahoo, MSN) and black hat SEOs will use any method they can to promote their site while trying to avoid getting banned. Gray hats are somewhere in between these two extremes.
So what sort of things constitute black hat SEO? There are three main areas where black hat SEOs operate.
The most common area is hidden text which is text that is embedded in the html code and seen by the search engines but not seen by website visitors. You can see some real examples of the many techniques used in this previous post hidden text.
The second area is showing one page to the search engines and a different page to humans. This is called cloaking and one method in particular is used almost exclusively, it is called IP cloaking. Here a software switch monitors the IP address of a user and compares it to a database of known Search Engine IP addresses. If the IP address is not recognized as belonging to a Search Engine the user is switched to pages designed for human consumption. If the IP address is determined to be from a search engine it is allowed to proceed to pages that have been specially designed for search engines only. If you want to know more about this technique you can read about commercial software available for IP cloaking at KloakIt and fantomas.
The third area of operation is content generation. Here the black hat SEO takes content (freely available articles from a database for example) and uses software to rewrite them automatically to produce original and unique keyword rich content for the search engines. You can see examples of such sophisticated software here and here. Content generation is even offered on external servers like TurboSM and it has now become possible to generate millions of pages for thousands of domains with very little effort. Adendum: August 30, 2006. Content generation software is getting better or so it seems from the look of this product here.
None of these techniques are useful for small business owners or anyone interested in the long term optimization of their site. It is however important to know that they exist and if you do come across your competition using such methods here is what you can do Google, Yahoo and MSN.