Here is some useful information
Great advice from SEOmoz, which I would like to share with you:
Semantically related keywords
You optimize your content for specific keywords. Apart from those main keywords, your text should also contain words, which are semantically related with your main keywords. This is something the Google bot is looking for. For example: the word cat relates to tiger, cat food, pet.
Section analysis
The Google bot analyses the sections on your page. Your main text, your side bar, the link sections, the footer. It is easy to see that not all sections are related to the main topic of the page. Still, you should keep your main text closely related to the title of your page. It is good to have semantically related keywords in the paragraph, but try to stick to your main theme, for otherwise you can end up ranking for tiger, instead of cat.
Linking out to quality content
Google claim they take into consideration the outbound links from your pages. If you link out to quality sites, this is a good sign for them. The New York Times followed this advice and they say it really lead to higher rankings in Google.
The outgoing links are also a good way to get into other people stat reports as referring sites. This may get them link to some of your articles as well. Linking out to quality content is a good link-building tactics.
Make visitors happy
Google have many ways to gather data how users react on your site. They have Google Chrome (their browser is already used by 25% of the webbers), Google toolbar, free Google Wi-Fi, they have relations with ISPs. These means allow them to see how many time visitors stay on your site, do they browse other pages, do they return to your pages, which equals to the way they like your site. If users like your site, Google will see it, so invest it that.
Quality content
The quality of your content is the best way to make your visitors happy. So, make sure your content is:
grammatically correct;
unique – it is a bad idea to have a template content and change 5 words on each page;
attractive to your users by including images and video;
made more interesting with user generated content. (Read more about High-quality content guidelines after Google Panda)
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