Move to the top of the search results pages, increase your visibility, drive traffic to your site—with these promises, it is easy to understand why many companies are tempted to avail of the services of a search engine marketing company that use optimization techniques search engines like Google and Yahoo! consider illegal.

Known as Black Hat SEO, these methods include adding hidden texts, creating doorway pages (or, as Google defined them “pages created just for search engines”), key word stuffing (i.e., bombarding your content with too much keywords and phrases), using popular but irrelevant keywords and participating in link farms.

Despite the potential benefits they can provide you, however, Black Hat SEO should be avoided like a plague.

First of all, the search engines could drop your rankings so low that even the most diligent of searchers would have a hard time finding your site. And a lowered ranking, as any business whose web site has been penalized can tell you, is never a good thing. Kinderstart, a parenting web site for example, experienced a 70% decline in traffic and 80% revenue decrease after Google penalized the site in March 2005 for allegedly using Black Hat SEO techniques.

And if you think getting your ranks lowered is bad enough, then read this: in some cases, the search engines even ban sites and remove them from their index list—this means that, unless you're able to successfully appeal your case, your site will never appear on search engine results page ever again. One example is the case of RICOH Germany. The German web site of the Japanese office-products manufacturer was “de-listed” by Google after the search engine discovered the site using spam techniques to bolster its rankings (the site has been re-listed after the company apologized and its webmaster made the modifications Google demanded).

If you're really unlucky, aside from getting your site removed from the list, you might also suffer from the same embarrassing fate of BMW.de. While the banning of web sites are never really announced (even to the company that owns it), Google's engineer Mike Cutts announced on his blog the removal of BMW.de's site from the search engine's index and even detailed the violations the web site committed. According to Mr. Cutts, the web site was banned because it used “doorway pages”. Reprimanding the site, he wrote, “That's a violation of our webmaster quality guidelines, specifically the principle of ‘Don't deceive your users or present different content to search engines than you display to users'.”

To avoid getting penalized or banned, hire a reputable search engine optimization company and ensure that only white-hat SEO tactics will be used. Remember, as great as the promise of improved ranking may sound, the penalties the search engines could impose upon your site once you've been discovered to be employing the unscrupulous techniques are even greater.