Using unrelated keywords: Web content should not use unrelated or irrelevant keywords. A real estate site should give information on real estate related issues. It should not contain any unrelated keywords like “free, buy, mp3, and cannon, Pamela or Monica Lewinsky….etc” unnecessarily. Web masters do have tendency to stuff their content with unrelated keywords for attracting visitors looking for another topic. This keyword stuffing is a well known method spamming.
Keyword stuffing: Using useless unrelated sentences or keywords or phrases inside graphic images or CSS layers or within the “alt” tags is known as keyword stuffing. Often described as “keyword Stacking” too.
Keyword stacking: Repeated use of keywords over and over again in title tag, meta tag, header tag as well as in web content is known as keyword stuffing. Example: A title tag like “web development, web development, web development…etc” will be considered as spamming.
Using tiny text: Text having very small font size or negative font size. Normal visitor can not see this texts but this text can be keyword reach text, used simply to boost up the relevancy factors.
Using hidden text: Text having same font color as background color. This method used to hide text. To hide unrelated keywords or repeated use of keywords this method is used. Normal visitors cannot detect or cannot see this hidden texts but search engine can crawl and can index this type of pages. To raise the relevancy factors web masters often use this unethical tricks.