Repeating Keywords – Some Web sites tend to repeat the same keywords over and over again, by hiding them in the invisible HTML code, invisible layers such as <NOFRAMES>, and in meta-tags. You do not want search engines to tax the Web site ranking due to excessive keyword repeatition.
Keyword Stacking – Example of keyword stacking could result from descriptive text in an ALT tag for the spacer image. Website designers use spacer images for properly spacing items on a Web page. But, you should not intentionally or accidentally cause Keyword stacking to occur.
Hidden text & links – Avoid inserting hidden text and links in your Web site just so as you can cover more Keywords.
Frequent & Misleading Title Changes – Making frequent and regular title changes will cause the bots think that your site is new and list you again.
Page Swapping – The practice of showing one page to the search engine and a different one to the visitor is know as Page swapping.
Content Duplication – If you have a Web page that is ranking good in search engines and if you decide to duplicate the same content on another page, and if search engine can track that, your site will be penalized.
Domain Duplication or Spam – If you duplicate entire content of one domain onto another on a different url would hurt you more than help if search engines can track this kind of activity.
Cyber Squatting – What if you launch a Web site called “Microosoft.com” or “Gooogle.com” or “Yahhoo.com”. These kind of domain names in a way steals traffic from the original website due to typographical errors and the visitor tends to land on this mistaken websites. As far as search engines are concerned, Google doesn’t like the implementation of cyber-squatting.
Cloaking – Cloaking is the practice of showing different content to the spiders that crawl your site than you show to your actual visitor.
Link Farms – Just say no to link farms. Link farms are sites whose only purpose is to artificially inflate link popularity through link exchanges. Google knows who they are, and if they’re not on their list yet, you can bet they will be soon.