Search Engine Optimization – SEO – may not be a rocket science, but still there is a logic and little bit of science behind it. Writing great content and being active on social sites, does not necessarily mean you will rank good on search engines. Although you may be following Google guidelines here, but still you are ignoring the ranking signals (factors) used by search engines.
Great content is not all about putting great stuff, but also about optimizing it so search engines can crawl and rank it on right keywords. What is the use of putting out a content which cannot be found on search engines? Therefore, keep in mind the search engine ranking signals as well when writing content or creating a website.
There are too many ranking signals used by search engine and it is a pain to remember all of them. Therefore, to ease our pain of remembering all of them, Search Engine Land and Column Five Media came up with the Periodic Table of Search Engine Ranking Factors.