How not to undertake search engine optimisation and how to spot dodgy practices that will kill your site rankings
There are many good professional SEO companies around but sadly the industry is so new, and understanding of the internet in the general business community so poor, that it is still bedeviled by get-rich-quick operations which promise fast and dramatic results by using shady techniques that are likely to harm your site in the medium to long term. Here we discuss some of those techniques and how to identify if someone is offering you them or if you have previously been the victim of them.
Still amazingly common, this technique simply adds lots of keyword rich text to your pages in a way that is either completely invisible or isn't easily visible to the user.
Various methods are used to hide this text. Sometimes it is simply set to the same colour as the background. If you see a large area of blank space in a page try dragging your mouse across it while holding down the mouse button. If there is text there you'll see it highlighted. If you find any on your site get rid of it immediately!
Try viewing the source code of your site. Are there any paragraphs of text there that you don't see on the page? If so they may be hidden by various means. There may be a style applied to them that makes them invisible such as display: none - this could be either in-line or via a style sheet. They could also be in an absolutely positioned div which is set to be off-screen; making it left: -1000px for instance. The idea here is that the search engines will read the text in the code and give the page more importance because of it, without cluttering up the graphics-heavy pages with all that nasty text. This is often used as a shortcut where a company doesn't want to redesign their site. However the search engines can increasingly detect this sort of disguise and will penalise you for it. Get rid of it!
Often closely related to hidden text, keyword stuffing attempts to further increase the appearance of keywords by inserting it in any place that it can go. ALT tags are a prime target - sometimes you will find images that have long sections of keywords added to both their alt tags and their title tags. Such tags should be used only for their proper purposes; the alt tag is there for people viewing the page with images turned off and for visually impaired people using screen readers, and it should contain enough information to tell them what the images contain and nothing more.
There are a number of ways that duplicate content can be used in an unethical manner. Having set up a site you can purchase another domain name and then put a copy of the same site up on that domain address. Sometimes this is done with completely different addresses and sometimes with different suffixes of the same domain - so you may have www.dodgyseo.com, www.dodgyseo.co.uk, www.dodgyseo.org etc. The idea is to have multiple sites all ranking in the top ten and squeezing out anyone else.
Again the search engines have got wise to this and if they find duplicate content then they will remove the duplicates from their indexes and may even remove the "original" if they think it was deliberate. If you have multiple sites with the same content get rid of the duplicates. If you want to use the domain names then either put up separate sites on them or point them at your main site using either DNS redirection or 301 redirects.
There is another nasty technique involving duplicate content - stealing someone else's. The unethical optimiser checks the rankings for the search term he's interested in, goes to the site that is number one, and steals their text to put on his own site in the hope that it is the text that is producing the ranking. Of course this is a clear breach of copyright. If you find that someone has stolen your text then you should threaten them with prosecution and make them remove it.