Spam refers to content on your Web page that the search engines consider to be an unacceptable tactic to gain a top ranking. Some search engines will ban Web sites or refuse to index the page if they catch you spamming. Exactly what is considered to be spam can vary for each search engine. Examples of spam for most search engines are using the same color text as the background, excessively repeating a keyword on the page, or optimizing for keywords that do not apply to your Web site. WebPosition's Page Critic provides further details regarding what 's considered spam.