What constitutes search engine Spam?

Any optimization method or practice employed solely to deceive the search engines for the purpose of increasing rankings is considered Spam. Some techniques are clearly considered as an attempt to Spam the engines. Where possible, you should avoid these:

1. Keyword stuffing: This is the repeated use of a word to increase its frequency on a page. Search engines now have the ability to analyze a page and determine whether the frequency is above a "normal" level in proportion to the rest of the words in the document.
2. Invisible text: Some webmasters stuff keywords at the bottom of a page and make their text color the same as that of the page background. This is also detectable by the engines.
3. Tiny text: Same as invisible text but with tiny, illegible text.
4. Page redirects: Some engines, especially Infoseek, do not like pages that take the user to another page without his or her intervention, e.g. using META refresh tags, Cgi scripts, Java, JavaScript, or server side techniques.
5. Meta tags stuffing: Do not repeat your keywords in the Meta tags more than once, and do not use keywords that are unrelated to your site's content.
6. Do not create doorways.
7. Do not submit the same page more than once on the same day to the same search engine.
8. Do not submit virtually identical pages, i.e. do not simply duplicate a web page, give the copies different file names, and submit them all. That will be interpreted as an attempt to flood the engine.
9. Do not submit more than the allowed number of pages per engine per day or week. Each engine has a limit on how many pages you can manually submit to it using its online forms.
10. Do not participate in link farms or link exchange programs. Search engines consider link farms and link exchange programs as spam, as they have only one purpose - to artificially inflate a site's link popularity, by exchanging links with other participants.