Keyword stuffing is considered to be an unethical Search engine optimization (SEO) technique. Keyword stuffing occurs when a web page is loaded with keywords in the meta tags or in content. The repetition of words in meta tags, may explain why many search engines no longer use these tags.
Keyword stuffing is used is to obtain maximum search engine ranking and visibility for particular phrases. A word that is repeated too often may raise a red flag to search engines.
Hiding text out of view of the visitor is done in many different ways. Text colored to blend with the background, CSS “Z” positioning to place text “behind” an image – and therefore out of view of the visitor – and CSS absolute positioning to have the text positioned several feet away from the page center, are all common techniques. As of 2005, some of these invisible text techniques can be detected by major search engines.
“Noscript” tags are another way to place hidden content within a page. While they are a valid optimization method for displaying an alternative representation of scripted content, they may be abused, since search engines may index content that is invisible to most visitors.
Inserted text sometimes includes words that are frequently searched (such as “sex”) even if those terms bear little connection to the content of a page, in order to attract traffic to advert-driven pages.