Continuing with Google's Webmaster Guidelines, the emphasis in this post is on quality content. As Internet use grew organically, there is a plethora of deadwood and duplication that Google has taken upon itself to tidy up using the 'land fill' method. Current and future websites should abide by Google's rules or they may never find themselves.
A very good tip is to create content for users, as if you were presenting to humans. That done, the code and meta data should reflect the content accurately. In other words, if it isn't good enough for humans to see, the search engines don't want to see it either.
This includes hidden text, such as using white text on a white background. Google will find it and you will be punished.
Another bright idea that isn't worth trying is creating a number of pages with generally similar content to use keywords that didn't make it onto other pages - for example, repeating a page of content that describes a product or service and just changing a few words, such as a colour or location. Google referred to their culling of Duplicate Content as their Panda sweep which aims to downgrade 'doorway' pages or affiliate websites that contain very little original content and are created purely as a search engine promotion tool.
Establishing links to your website is a tricky business. There are several companies that offer to provide 100 or 1000 links for a fee. If you can't verify the list, think carefully about its value - Google's Penguin update downgraded websites that it deemed to have participated in low level link schemes. Google is happy to see reciprocal links that have been carefully considered and loves links from related unique blog content.
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