A few words about Black-hat SEO methods: 

Many people have heard the phrase "black hat" SEO but do not actually know what the phrase represents or means. Generally, the term represents a website's efforts to deceive its visitors by offering products, services, or information it does not actually provide. Often the term conjures up thoughts of "magical codes" or "tricking" the search engines to find a website that otherwise would not be found.  This is not the case however.  There are no magical codes, or tricks that can be applied to the search engines. No so called website Guru has such ability.  However, it is possible for a website owner to deceive his visitors, and those of the search engine by placing deceptive information on the site. 

One analogy can be used by someone placing a newspaper ad for a car at $10,000 to get you interested, only to later say 'that car is gone but I have a $20,000 car available".  This would be a deceptive practice and would discredit the seller's credibility.  Google in particular, but also other search engines try to protect their website visitors from this sort of deception.  We applaud them for doing so because the future of the internet depends on integrity.  

Similarly, the credibility of the search engine results is dependent on the reliability of the information given to the search engine visitor.  In other words, it is important to Google, Yahoo, Msn, and the others, that the information provided on their website is accurate and to the point.  Deceptive information would tend to lesson the value of the search results and thus damage its credibility.

Another example of deceptive practices would be to place words on the website which have no value to the website visitor but are solely used to attract the search engines.  Most frequently this can take the form of invisible words (words having the same font color as the background) that are used to draw huge numbers of visitors to the site solely for the sake of traffic, and without regard to visitor value. This is easily detectable by simply using the mouse to scroll over the empty space in a website while holding down the left button.  Any words detected can be considered either an error on the website developer’s part, or black hat SEO tactics. 

To sum it up, your website can be a search engine friend or foe.  Provide what you say you provide and you will be their friend.  Deceive your visitors by false, misleading, or hidden information, and you will be their foe.  In short, there is no future for your website if you attempt to deceive either your visitors or those of the search engines.