The controversy regarding Black Hat SEO techniques and White Hat SEO techniques has existed since search engine optimization emerged as a viable method for promoting a Web site in the late 1990s. Each offers a different approach to optimizing a Web site for higher organic or natural "free" search engine rankings. Both methods do work, but in different ways.

The White Hat approach to SEO focuses on using clean code and proven optimization techniques, while avoiding all issues that could result in a penalty from a search engine. Penalties are commonly placed on Web sites for a wide range of infractions. Most penalties result in reduced rank positions for a site. Penalties for egregious violations may result in the banning of a site, which is the complete removal of a site from a search engine's database. If your Web site is banned from a major search engine like Google, you risk losing about 60% or the traffic to your site from Google and affiliated search engines such as AOL and Netscape.

The major search engines never notify a site owner about a penalty and only rarely acknowledge a penalty when contacted. Unless the penalty situation is resolved, a Web site can exist for years in a low ranking position without any other indication that a penalty has been applied. Once a penalty situation has been identified and corrected, a Web site frequently rises to a higher ranking position. White Hat SEO therefore seeks to identify, correct and avoid all situations that have the potential for creating a penalty.

The Black Hat approach to SEO focuses on doing "whatever it takes" to achieve a higher ranking position. This usually means an intentional disregard for search engine rules in order to achieve an advantage over other sites ranked for the same keywords. Black hat techniques are synonymous with search engine spam, which is basically any method intended to artificially boost a site's rankings and specifically disallowed in the search engine guidelines.