There are more and more ways for websites to be banned or penalized by Google search engine. As such, every Webmaster should be wary. This isn't something to be taken lightly.

Getting banned or punished by major search engines is the last thing that we want our websites to experience. As much as possible we stay away from online activities that will elicit the wrath of web search engines. What are these activities, by the way?

One of the most popular ways that your website could be banned is from buying or selling paid links. You must've heard about those unfortunate sites. Do you know the story about Aviva and Alive directories? I suppose so.

Both directories were dropped from Google SERPs. Why? Because Buying or selling links that pass Page Rank is in violation of Google's webmaster guidelines. Violating the guidelines will definitely compromise your site's search engine rankings. Many webmasters are guilty of this technique.

To remedy this plight, Google said don't sell or purchase links. But if you want to continue, just be careful. Apparently, Google will continue protecting AdWords.

Aside from the mentioned technique, other webmasters are using duplicate content and ghost/doorway pages. If I were you, I will avoid those techniques to avoid your sites from going down the drain.