It is extremely important to know what search engines don't want. Therefore, when you learn about factors that influence search engine rankings, you should also learn what tactics to avoid. Spam - search engines' worst enemy Search engines hate tactics intended to fool them into awarding high rankings to irrelevant pages. Search engines strive to provide the most relevant results to their users, but spam clutters their indices with irrelevant information.
Some webmasters create spam after they learn which criteria search engines use to rank pages.
For example, search engines give high scores to pages filled with keywords. Webmasters came up with a way to add more keywords without sacrificing a site's appearance. Previously, robots that indexed invisible keywords ranked those sites higher for keyword frequency and weight . Search engines now know of this technique and define it as spam. Currently, sites that use invisible text are banned from most of the major search engines.