Sending a large number of messages to users that did not ask for them.
Also, a term used to describe when a website designer incorporates extra and irrelevant information on a web page, usually as word lists or as text hidden in the background, for the purpose of making the search engines find these words and display their site at the top of the index listing. T
his practice interferes with providing others with quality searches and is strongly discouraged.
When detected, some search engines will automatically remove the pages from their index.