There is a plethora of sites, blogs and online articles out there on the Web to tell you all the things you should be doing to improve your rankings and performance on the search engines. A lot of the tips and techniques mentioned by these online SEO gurus are useful - but most of the time, they don't tell you what you should not be doing while optimising your site. In this article, Livewire lists the four Cardinal Sins of SEO... commit them, and you could get banned by the Big Three, that is, Google, Yahoo and MSN.

Cardinal Sin One

You have always been told to choose your keywords carefully, and then optimise them across the pages of your website. So far so good. What you should not do is over-optimise keywords and key phrases. Search Engines are more intelligent than you may think - they can spot unnatural concatenations of keywords and phrases. These engines have a clear preference for natural flowing text with the proper density of keywords embedded within them. Google prefers a keyword density of 3 to 5 per cent; Yahoo prefers 7 per cent. Go overboard on keyword density and the Search Engines will punish you for your sin by ignoring you.

Cardinal Sin Two

Don't optimise pages with a very wide number of totally unrelated keywords. When a site contained bunches of diverse, unrelated keywords or phrases, the Search Engines actually get confused - they can't figure out which category to place the site in. Result: they ignore the site. All your SEO-related blood, sweat and tears are wasted!

Cardinal Sin Three

Some people think that a clever way to deceive the Search Engines is by creating duplicate pages across the site. This is big no-no. Instead of better rankings, what will actually happen is that the Search Engines will not index your website. Worse still, your site could be flagged by the Search Engines as Spam. And in extreme cases, the Big Three could end up banning your site.

Cardinal Sin Four

Never, never use hidden text to improve your Search Engine rankings. Hidden text are words that your website visitor can't see, but are placed on the page for Search Engines to read - for example, white text on a white background or black text on a black background. This is outright unethical, and the Search Engines abhor such dirty tricks. The punishment for this sin is clear - in all probability, you will be banned by the Big Three.