For every online marketing company it is a dream to get top positioning in the SERPs of Google. Though it is difficult to find out Google’s algorithm still it is a known fact that the search engine penalizes the sites that are using any unethical techniques for search engine optimization and trying to get a high positioning in search engine result pages. Having numerous techniques available to influence the search engines it is advised that one should not use any techniques that would result in penalty for the site. The ultimate penalty that Google puts against a site is to ban it from getting indexed.

There are some practices of SEO known as black hat techniques, using which can result in a ban on the site, by Google. 

Spam - Spamming includes sending large number of unsolicited mails through your domain server. Sites which practice this are banned by search engines.

Stuffing - Stuffing the keywords in the main text and the Meta tags merely for the sake of search engines will eventually take the site to get banned from the search engine indexing.

Link Farm - Link farms are mostly looked down upon by the search engines as they are creator of spam. As link popularity is the most important thing to consider some sites opt for getting links from link farm. As these links are not from relevant sites, bad link strategies can lead to ban from search engines.

Cloaking - Cloaking is a black hat SEO technique, using which one page is designed for the search engine and another for the human visitors. It is designed mainly to deceive the search engine. This kind of manipulation will lead to penalization like banning.

Doorway Pages - Doorway pages are designed stuffed with keywords to get a high rank in the search engine result pages. With this spam technique it is obvious that a site is being penalized.

Unethical Linking - Sometimes webmasters create multiple sites just to link to each other and increase link popularity. Sometimes there are too many outbound links from a single site. Both are not recommended for search engine optimization.

Unauthorized Software - Use of unauthorized software to submit pages or for checking rankings violates Google’s terms of service.

Webmasters use blackhat techniques to influence the search engine results. There may be a period of time when they succeed in doing this. But that is a temporary success. After been found out the sites are banned completely by Google. While doing SEO on your site or hiring any company to do that for you it is important to take care that no unethical practice is going on with it. Though time-consuming, but a white hat optimization is the sure fire way for long term success.